If you think about it, it kind of goes back to the original old debate of the Haunted Mansion: Funny, or scary?
The thing about the new bride is the story and the concept of the bride is actually dark when you really think about it, but the punny lines and (to me) forced way of (trying to) make her look intimidating makes it more light.
Also, just because she's eyeroll worthy to a lot of people, doesn't necessarily mean for kids it's the same. Some kids might think she's not scary either, but some kids might.
So, like I said, it goes back to the old debate of funny, or scary.
I'm not in favor of the new bride either, but just opening up the possibility that she might be this way for a reason.
I like both the 'beating heart' as well as the Constance version of the bride (and the changing portraits that accompany her are pretty neat). I sort of wish there was a compromise between the two, a more subtile and mysterious Constance.
Of course if she gains a companion in the Attic who loves hats, they might have to change the scene to connect the two characters more and that would be a good time for the next variation of the bride.