A friend of mine made a comment which rang true to me. D&D is actually two games (So is Pathfinder, but if I say Pathfinder and D&D are actually two games, that just confuses the matter, because they are very similar in the fact that they are two games)

Part of D&D is dungeon-delving and being Big Damn Heroes saving dragons and slaying princesses evil queens, where everyone has to work together to defeat [Menace].

The other part of D&D is magical God-Kings playing xanatos speed chess.

The Tier 1 classes have (to varying degrees) been given tools to play in both of these games. The 'Martials' have been given the tools to play in one of them.

Unfortunately for the Martials, the game makes a natural progression from one to the other, by dint of the options that got published options. When level 15 rolls around, the fighter and ranger are still getting options to face down combat encounters. Really nasty combat encounters, but combat encounters. Casters are getting spells like Guards & Wards, Greater Teleport or Forbiddance

So there's a fundamental disconnect in what classes are able to. Fighters could have been given feats which let them strike before immediate action teleportation, or hack spells in half, but they weren't.

So as people who enjoy playing martials, who start out contributing in very obvious ways while their friends around the table are also contributing in obvious ways, slowly find that their character is becoming sidelined (unless the GM is very careful) and then they're stuck in the middle of the plot with characters who they're invested in who just...aren't useful, and there is little recourse to actually fix this in progression, because the PRCs that are open to them are often too little too late (most Gishes, and they require casting anyway), or have restricted flavour (Ur-Priest).

That's my 2c, anyway.