Why do you say this? I don't have 4 hours right now and would appreciate a TLDR.
Take a look at industrial cobots (not a typo). They feature rounded corners, have very little to no "finger pinchy areas" and lots of force feedback sensors.
Despite that they still require trained (adult) personal and move very slowly when actually interacting with humans.
That's the price for them being sturdy and precise.
Imagineering is trying to build the coolest things possible, and many times the things seen in parks are play-tests.
Operations has to find the money and resources to keep things going, and these things take a lot of people to run.
Marketing sometimes will often provide the budget to make things happen (to promote a movie, etc) but it's not sustainable. They'll often sometimes use impractical inventions for marketing reasons, since they exist and might as well be used for something.
That's the main gist, although there's some interesting points about the risk to the brand (especially with camera phones) if Mickey ever slightly malfunctions in a public setting.