The thing is, whether I use D20/D&D3.* or Pathfinder, if I decide to build a Grapple specialist, or a Trip specialist, or any other combat maneuver, I can choose weapons and feats that stack my bonuses to "startlingly high".
And I'm not sure that's a bad thing.
I built a trip-monster once. Spiked chain, high Strength, access to Enlarge Person, and the Improved Trip feat. I also added Combat Reflexes, of course. One DM balked, seeing what his Trip bonus was (Under D&D 3.5 rules it was +6 for Strength when enlarged, +4 for Size and +4 for the Feat) for a total of +14. Improved Trip isn't BAB based, so it was as effective against higher level monsters as it was at lower levels. He let the character in (It was a pick up game at a Convention), but was worried that I'd be abusive.
As we played, though, he realized that, while the character was hell on wheels in a swarm-attack situation, he lacked certain feats that he considered common for a melee combat type. That's when it became clear that my specialty came at a price: I'd had to spend Feats for Exotic Weapon - Spiked Chain, Combat Expertise (Pre-req for Combat Reflexes), Combat Reflexes, and then Improved Trip. I'd also had to take a 1 level dip into Wizard to get access to Enlarge Person. That makes it essentially a feat tree four levels deep. And those four Feats that I'd spent on that were Feats I didn't have for things like Weapon Focus, Weapon Specialization, Dodge, Mobility, Power Attack, Cleave, Great Cleave, etc.
Now, those weren't the only Feats he had, and he wasn't missing all of those I listed, but Cleave wasn't there, nor were any of it's children. Dodge and Mobility weren't there. Since at least part of his build was Ranger he had some archery skill, but lacked Point Blank and Precise Shot.
So I can see where characters (or monsters) that specialize in combat maneuvers might make DMs uncomfortable, if only because it's not something they see very often, but since those tricks come at a price, it's not as unbalancing as some might first think.
Now, does that mean that the 3.5 or Pathfinder rules are balanced or easy to use? Of course not. But "fixes" that have the result of eliminating the maneuvers from play aren't fixes at all. (Unless you're thinking of "taking your dog to the vet" kind of fix, that is.)