The drummer is usually the first guy to lay down tracks. This means he is the guy laying down the foundation on which the rest of the song is built. If he can't lay down a solid groove, or lock onto the click track, it's going to be blatantly obvious. The more tracks that are recorded, the easier it is to hide mistakes. Many semi-pro engineer/producers get more and more lazy as the tracks are going down. Meaning, after the drums and bass are 'perfect,' they let their ears relax, and timing or groove problems get passed over for other instruments.
I've had sessions where I knew my drum part was locked in with the click or the sequenced parts, because the producer wouldn't let me leave until they were.

Because of this, I knew beyond a doubt, that my parts were rock solid. Months later, when I hear the final tracks, the rhythm section is horrible. Nothing is tight, and the groove is sloppy. If *every* musician isn't held to the same standards as the first guys in, then *everybody* ends up sounding bad.
Another reason for drummers getting dissed, is that we seem to overplay, until we grow more as musicians. Anymore, when I'm in a session, I try to play as little as possible. Then I cut that in half.

All the tastiest grooves ever recorded, have been pretty simple. Drummers who laid down the best songs, have played very few, and very simple fills. Think Gadd, Porcaro, Ringo, etc.
Always leave them wanting more, not less. The best compliment in the world is, 'we want more.' The worst criticism is, 'we need less.'
