Like others have said for us it is location and room size. As a family of 5 I would have to get two rooms or a suite at other resorts including WL and AKL.
I also have to agree with the above poster. For what I paid for my room at the W in Chicago I could have stayed at the GF and trust me, there is no comparison. We are planning a quick ski trip to the poconos and the "resorts" there are outrageously priced for run down accomodations. I would much rather be in a Disney hotel I can get for that price.
Although Disney is not cheap by any means, I personally feel they are a decent value. When I look at what other hotels cost at vacation locations I think the Disney resorts are nice and well maintained. The convenience, added benefits, and location make them worth their cost IMHO even though not everyone agrees.