Now, at the outset: In and of itself, movies being added as elements to the park in attraction format isn't a bad thing to my way of thinking. This topic is about what has changed in the manner of presentation, and whether or not such rides are viewed overall as classic/fun or just...sort of blah to being downright unrelated to where they are added.
A bit of history: Disneyland opened with attractions based on then-current or some not even released yet movies (Sleeping Beauty's Castle for one). Therefore, not all were "classics" at that point: Alice in Wonderland was a film Walt recognized personally as being less than pleased with from his own point of view, final product-wise. Mickey and the gang weren't associated with the park as icons in the early days even: that duty was given to Tinkerbell and Dumbo mainly.
In making the early Fantasyland rides, apart from Dumbo, it is also interesting to note they very consciously did not feature the main character of the film being told. Alice was not in Alice in Wonderland, Snow White was absent from her ride, and of course in Mr. Toad, guests acted out his role in driving their motorcars to nowhere in particular. This meant the secondary characters or villains mostly ruled the show, combined with a compelling or exotic atmosphere: the strange woods and environs of Wonderland, the dwarf's diamond mine and evil castle of the Witch, the backstreets and countryside of England, or flying over Neverland. Environment was a huge factor in choosing which properties to make into attractions. As was later said during the seventies by an insider, a Robin Hood dark ride was proposed then rejected since it was just woods after woods after woods, with introducing new characters along the way.
The Fantasyland rides would eventually change to feature their main characters come 1983 and the very successful redo of that area of the park. However, at that point, it was adding characters in one or two spots for most (Mr. Toad still isn't appearing in AA form in Toad Hall), in rides already themed to their adventures. No problem there.
After the park's initial opening, it was inevitable new attractions would be created, and these also managed the balance of interesting characters in well-themed and unique environments. The two rides currently considered Disneyland's "crown jewels", Pirates of the Caribbean and Haunted Mansion, are stellar examples of this. The marriage of character to environment is very strong and interwoven, even to the point of having areas in HM with zero visible characters (the stretching room, portrait hall, the corridor of doors) and only a disembodied voice addressing guests.
With the advent of outside properties to Disneyland in the 80's and 90's, such as Star Tours and Indiana Jones, this of course brought new characters who would rightfully star in their attractions. However, environment was still key in making the attractions work: the focus was equal both on the ancient, foreboding temple and Dr. Jones himself. It was a complete package, both elements making up the tone of the films they were taken from. Over at Star Tours, the overall experience was of exploring a new area of the filmic universe: a tourism agency set up as if it was an ingrained part of that world. Familiar characters worked alongside new ones in service of making a believable entry point into the world of Star Wars, and it did not turn into a experience of trying to cram in endless movie characters where they didn't fit into the story being told.
The same is true for Splash Mountain, featuring a new cast of critters alongside the stars of Song of the South. The watery ride had tons of environment and ambiance married to the music and tone of the film. The same with Roger Rabbit: the noir-ish aspects of the backstreets of Toontown coupled nicely with the cartoon style gags and characters used. All was still in balance.
I think the main issue today is the tipping of the balance. Current movies used for inspiration certainly may be classic someday, or are now: Toy Story, for example. However, somewhere along the line, then creation of a compelling and realistic, fascinating environment seems to have fallen by the wayside.
Consider, if you will, Swiss Family Robinson. Prior to the late 90's, it was a still display all about the tree, the scenes within, and the sense of adventure and romance of living in a remote tropical jungle and all it entailed. There was not a scene by scene breakdown of the film. It required imagination. It may not have been the most thrilling attraction or as popular in recent years, granted, but it had a theme and purpose outside of showing every aspect of a feature film. When Tarzan moved in, basically, the tree was just a template. It didn't matter much to the overall goal. The focus was on re-telling, via books along the way, and static figures, the exact story of portions of the movie. Characters were in, making it about ambiance was out.
The same has happened, in varying degrees, all over the parks. The current crop of additions by and large has swung the focus solely on popular characters and less about transporting you to the world of a film, or conveying the emotion or story in an exciting manner: Buzz Lightyear's Astro Blasters, Toy Story Midway Mania, The Many Adventures of Winnie The Pooh, Finding Nemo Submarine Voyage, etc etc. These rides are all about character, by and large. Putting the character right there in the forefront and retelling their story in some format, as opposed to making the experience be about going on a journey into a richly themed environment.
It has even progressed to the addition of characters into existing 'classic' attractions: Small World, Pirates, The Tiki Room in Florida. Regardless of level of skill and integration of these elements (very poorly done at Tiki Room) it remains true that adding such movie characters is changing the whole experience from being adventure and escape based, or about a theme, to essentially being a showcase for one certain character or a group of characters. The story of Cinderella or Aladdin is not the story of It's A Small World, regardless of attempts to match the style of the installed new figures.
At this point, it seems the well-known characterless attraction may be a thing of the past for Disneyland. Even the themed roller coaster that exists outside a movie property base (Big Thunder Mountain, Space Mountain, Matterhorn -which in no way reflected the film story of Third Man on The Mountain) may be a thing of the past. Disney World received Expedition Everest and Mission: Space without movie tie-in's, but Disneyland seems set on a path of characters being the entire reason for adding new rides.
This can be done well, in some instances, but I daresay it shouldn't be the reason a attraction gets the green light. Adding a property based on a character moving merchandise, basically, is not what produces excellent experiences for the paying guest. Such rides can be fun, yes: I enjoy riding Midway Mania for one. But it doesn't hold a candle in my mind even to the "plain" characterless roller coaster that is Space Mountain, let alone something like Pirates or HM.
Just my two cents on the subject...movie properties aren't inherently bad, but the focus has shifted, I feel, too far off the mark of meeting the balance between making a movie based ride and creating a thrilling, independent theme park adventure. Universal Studios has shown they can merge amazingly popular characters with great theme and a exciting ride, seemingly, with The Wizarding World of Harry Potter...why can't Disney do the same anymore? They need to raise standard of simply making fun rides based on the cash-cow characters: to return to making engrossing attractions that guests can bring their imagination to, instead of retelling a movie beat by beat in ride-through format. They have done it before with successful properties, let's hope they do it again.