I think the whole feeling of it being rushed may be to keep that overwhelming feel.. but the Simpsons is just a very crazy show, and if it's gonna be turned into a theme park attraction, they're gonna cross all lines possible. I remember when my uncle and aunt went on it (mid-40s, so not too old!) and they needed to sit down for a while after riding it because they were just completely burnt out by all the overwhelming action happening around them all at once.
Anyways, the least they could do is give it more vibrance and appeal. You'd think such a chaotic cartoon world would have bolder, brighter colors.