For my money, the problem with Improved Grapple and Grapple in 3.X is multifold.
1) as noted above, its terribly easy for a monster to get a grapple modifier so high that only specialized PC's can avoid the effect.
2) lots and lots of monsters have improved grab, which makes it a more common effect than, Frex Hideous Laughter.
3) The grapple rules are poorly written and focus too much on weird corner cases (frex, stabbing a guy with his own weapon). Grapple thus slows down the game more than something like Hideous Laughter.
So you have a common effect that's hard for a majority of PC's to avoid that slows the game to a crawl when it comes up. Ack.