To be completely honest, I could never grasped what part in particular people dislike about 3.x grapple rules. In my opinion, they cover an entire subsection of combat, which has enough variety in it to support various real-world fighting arts/sports, without clogging up the game. The grapple rules offer a lot of things you can do IN a grapple, as well as some things you can do if you want to get out of it, or join it, or just take advantage of other people grappling each other. I think the system is well done, all in all.
Yes, it takes a few rolls - but after all, rolls aren't any more time-consuming than waiting on an individual player's tactical decisions. Some of my guys dither so much ("Power Attack for 2 or 3?", "risk an AoO to get a flank, or not?", "should I begin raging now, that's gonna hurt my AC so much!", "if I cast defensively I'll have a 75% chance to pull it off... should I risk it, or move first?", etc.) that it can be a boon for the game's flow when they're in a grapple. It provides some options, but not overly many, so all you have to do is look up some numbers and roll those dice, instead of falter in the face of so many decisions.
Furthermore, just like the AoO rules, certain conditions (level loss, entanglement etc.), certain spell categories (summons), certain class abilities (wildshape), grapple only takes some practice to get used to, and some preparation on the DM's part to use smoothly.
The grapple rules may feel a bit clunky, but so do other things in 3.x. Reducing grappling to a single roll, or even reducing ALL combat maneuvers to a single stat roll like Pathfinder does, takes out quite a bit of the game's spice for me.
/rant.