In an ideal world, sure. But put yourself in Disney's shoes. You can build a hotel and charge $450/night or one that you can charge $150/night. Either one will be packed from the day it opens. Which one do you build?
Both are important.
If a resort like the Pop Century averages at $150 with 2880 rooms, that's $432,000 a night. If you assume an average of 2 tickets per room at $100, that's another $576,00. So $1,008,000 a night. You also have to feed at least 5760 people.
If a resort like the Contemporary averages at $600 with 655 rooms, that's $393,000 a night. With tickets, that's another $131,000. So $524,000 a night. You also have to feed at least 1310 people.
The Contemporary requires less workers and the guests are more likely to spend more money per person in food and souvenirs, so the single guest at a deluxe is still more lucrative. Either way, Disney still makes a lot of money.
I think having a mixture of DVC, deluxe, moderate, family suites, campgrounds and value is important. With deluxe accommodations, you can charge more per room, but you have less rooms. That also means less people and less tickets. With value accommodations, you can have more people and sell more stuff, but it also costs more in labor and they're probably not buying the higher ticket items. I think they keep making DVC resorts because they can't keep DVC inventory. They're refurbishing all of the values, which is greatly needed. Maybe when they're done with the renovations we'll get a new All-Star Resort. Who knows, but given their occupancy rate I think they could definitely use it.
I personally think that they need a 5th gate. I know not everyone agrees with that, but maybe after he 50th the need will become more apparent. Alternatively, maybe the economy will take a hit and the people who said it's unnecessary will be proven right.