If there's anything I learned in 20 years of commercial software development work, it's that corporations don't spend on big development projects unless there's a business justification for it. And there's no business case to be made for this.
("Some customers would love it" isn't a business case. Neither is "Some other hotel chains do it.")
This would be a massive, expensive undertaking. Disney's IT is in-house custom development; they can't just go down to
Best Buy and grab a copy of Microsoft Room Picker for Customers. When all is said and done, probably millions of dollars. New software systems don't just cost whatever you have to pay the programmers. There's analysis. There's testing. There's documentation. There's hardware upgrades to support the extra processing. There's training for hundreds of impacted cast members. There's hiring call center staff to help people who will inevitably be confused by the web site changes. There's ongoing maintenance and upgrades. In order to justify spending that kind of money, they'd need evidence that the new functionality would either
a) save them more than they'd spend on it, or b) make them more than they'd spend on it.
I don't see how giving guests the ability to choose rooms would do either.
Disney competes in a very different market than short-stay chains that cater to business travelers like Hampton Inn/Hilton. They have to carve out ways to distinguish themselves from their competitors, because really, they're all very similar. Letting guests pick a room is a BIG difference in a market where there are hardly ever big differences, so yeah, I'm sure that was well worth the expense for Hilton.
Disney already has a boatload of amenities that distinguish themselves from the hotel competition in Central FL. When they're already offering free airport transportation and free on-site transportation and magic bands and a big advantage in booking FP's and meals and early entry into the parks, how many additional customers would the ability to choose a room really get them?