It is absolutely appropriate to provide additional perks to guests who pay more, whether it's a bigger room, a nicer pool, or more fast passes. A Disney trip costs money and Disney may change their pricing, or package conditions or ticket options as they see fit. Guests on the other hand are absolutely free to spend their money where they will. If a particular pricing scheme or policy doesn't win favor with the public, money won't be made. Essentially if a company, Disney included, fails to provide a product at a price the consumer finds acceptable, they will suffer. Disney apparently has done a pretty good job of providing what the customer wants, since people choose to spend their money there and I don't see that changing. And one point to remember, attractions aren't developed and built for free. Since I started going to WDW in 2003 any number of attractions have opened. Soarin, Finding Nemo, Journey of the Little Mermaid, New Fantasyland, Lights Motors Stunts, Toy Story Mania, Expedition Everest. These all in the past 10 years and I'm sure I missed a few. The people who object to Disney trying to increase revenue don't seem to mind the new attractions though.
Just my 2 cents.