Yeah it's definitely not a perfect system, no doubt. There is also the "golden parachute" issue that one hears about a lot, for example. Even so, I think market forces are still influential enough in this country to make companies responsive to customer preferences over the long term.
I think the situation with Disney has been a bit of an artificial bubble in that they've had next to no real competition for awhile. These are just my anecdotal impressions, of course. When I was growing up in the 80s Disney World was much smaller and other amusement parks were, it seems to me, overall better. Somewhere along the way Disney got huge and many other amusement parks got sketchy and shady, places that wild teens go to cut lines and act wild, not family vacation destinations. (Why that is, I'm not sure, there's probably an interesting story behind that trend.) Now, even Disney's competition like Universal and Lego World probably bring in a certain amount of business because Orlando is the epicenter of All Things Family Vacation (When Magical Express was cancelled, I noticed many families saying they were taking their family vacations at National Parks from now on, but come on, we all know this is an empty threat, the way that you say your kid isn't eating McDonald's anymore if they don't make healthier food. If you want to take your child on a dream vacation, there is just no comparison to the Orlando area anywhere. Hiking America's landmarks, for a five year old, is in no way shape or form the same as riding the Dumbo ride.)
Like I said though, I don't see that lasting forever. While, as you noted, capitalism in this country isn't perfectly fair, it's not going to prohibit Disney competitors from building if they choose to do so. (So that's what I mean by market forces - in some parts of the world I think you just don't compete with the top companies, period, on threat of your life and freedom. But in the US you can.) And if the opportunity is there, competition will emerge, eventually, and even out the market a bit. I predict that this competition will likely be local, at least for now (eventually frequent international travel may be more accessible for the average family, but I think that's a ways off)... places with some combination of a quaint historic town / wineries / beautiful scenic spot / historic site / etc. + some combination of indoor water park / adventure park / small nearby amusement park / spa / prepaid meal plan with over-the-top offerings (elaborate melon carvings or ice sculptures or whatever) / etc. I have to say that as a parent that's the only concept that kinda floats my boat in the same way that Disney does. You sacrifice some of the extravagance of Orlando but you gain the charm of a charming town and / or gorgeous nature, and you still have something magical to offer your child.