1. Myth: "I've never seen this problem, therefore it doesn't exist."
Answer: I've never been to China, but I don't deny its existence. I just haven't gone there.
2. Myth: "Any attempt at balancing classes inexorably leads to 4e!"
Response: ...except when it doesn't, like Frank and K's Tomes, or Szatany's Ultimate Classes, or Kirthfinder.
3. Myth: "Martials are supposed to be worse than casters -- it's more realistic!"
Response: No, not as long as a 10th level fighter PC and 10th level wizard PC are both CR 10. In that case, it's completely missing what a "character level" is.
4. Myth: "You just want fighters to teleport and throw fireballs!"
Answer: Hardly anyone is advocating anything like that. But fighters and rogues do need their own ways of meeting level-appropriate challenges. Even if those methods bear no resemblance to spells, they should still be able to get the job done.
5. Myth: "It's a team game, so it's OK if your class is weaker!"
Answer: No one wants to play Scrappy Doo when the rest of the party is the Avengers -- at least, not in a half-serious game.
6. "I never have this problem because the DM fixes it!"
Answer: Then you're playing storytime hour, not Pathfinder. If we fixed the problems, you could still play storytime hour, and we would BOTH win.
7. "I can still have fun playing a fighter/monk/rogue."
Answer: I can have fun playing a Commoner. That doesn't mean it's a viable class compared to the others.
8. Myth: "Fighters can do it all day long!"
Answer: Not if they run out of hp.
9. "My fighter is fine in combat!"
Answer: And if all there is to your game is lining up and blindly walking into staged combats, then the fighter is fine in your game, but he isn't in most other peoples' games. And it's not because of his attack bonus.
10. Myth: "Anyone who thinks fighters and rogues aren't fine is a Shroedinger Theorycrafter who never actually plays."
Answer: No, many of us saw just how badly the mundane classes lag by actually playing with people who weren't afraid to stop pulling their casters' punches. I never saw the disparity on paper until I saw it in play.
11. Myth: "Fighters are awesome because you can fix all their problems by spending more feats and money."
Answer: Even they don't get nearly enough feats for that, and they still get near-nothing for skills, and unless they get a bajillion gold as a class feature to spend on whatever they want, they can't possibly buy enough stuff to do their job and still shore up their glaring weaknesses.
12. Myth: "It's only a few vocal people who hate fighters and rogues who are trying to ruin it for the rest of us!"
Answer: Some of us LOVE fighters and rogues, and would like to be able to play them and still be something other than a caddy after 6th level.