Of all current attractions at Disneyland and DCA, which ones would you object to if they didn't already exist and WDI came out with a plan to build them? I know this if tough because many are so classic that Disneyland wouldn't be the same without them, even if they're not considered top-notch today.
Matterhorn? "We're going to build a replica of a famous mountain and run a rollercoaster through it"
Haunted Mansion? "We're going to build a haunted house where ghosts pop out from behind gravestones and you hear knocking on doors"
IASW? "A slow boat ride with singing dolls"
Note: I wouldn't object of any of these, I just wanted to post examples of iconic attractions.