That is true. Of course, if you perfected the way to avoid running into problems after 30 years of work, you'd likely be justifiably peeved to discover that your method has been tossed out the window, returning the problem while simultaneously undoing your work around. Especially if that work around has worked for such a long time.
Right?
RC
Has 3.5 stopped people playing 2e? Did 2e stop people playing 1e? If people are still playing older editions, the newer editions doesn't actually have an effect on them.
Basically, a new edition HAS to be different than the previous edition.
Each edition, in part, has to compete against the previous editions. They make a new edition "fixing" parts of the older editions. However most of the "problems" are something that, as the saying goes, may be a "feature not a bug". Some people are happy to have things change, like expanding the sweet spot from 1 to 30. Other people hate it, because they LIKED the way that things worked different at low levels, mid levels and high levels, as it relates to wizards.
So, you can either make a new edition with the same "feature not bugs". You are appealing to the people that like the old edition, are comfortable with the old edition, and aren't really looking for a new edition. OR, you can make a new edition that changes those things, for people that may be getting tired of the old edition and looking for a new one.
If WOTC felt that 3.5 was just about perfect ... and made a few changes and released it again ... they wouldn't attract people that may feel there are problems with 3.5, because most of the same problems would be there. And, a lot of the people that like 3.5 may not see a reason to abandon a "complete" edition with all the splat books, etc ... for a "new" edition. Pathfinder sort of accepts the fact that they can't reboot 3.5, and allow just about anything they didn't explicitly change from 3.5 to stay. Selling it as another expansion of 3.5 is one thing. A total reboot would have a very hard time competing.
So, in general, people that are overall happy with earlier editions may not be happy with newer editions. The new edition isn't necessarily indicating that there is something wrong with the older edition ... just that there are some things the older editions aren't necessarily good at. This edition tries to tackle that from a different angle.
Ultimately, someone who has found their "near perfect system" is likely not going to see WOTC release a new edition of D&D that they'll be happy with, because re-releasing the same game isn't going to happen. It already exists, and there is nothing stopping someone from playing it other than perhaps less players looking to play in a campaign of that edition.
Aside:
Defender/Striker/Controller/Leader isn't something they pulled out of WoW. 2e had Warrior/Rogue/Wizard/Priest. Warrior was a bit more strikerish, and the rogue's role was more of an out of combat role, but the foundations of the four basic roles were there ... following the original "only 4 classes" that came before it. 3e was really the only class to significantly go away from that idea of roles.