Frankly, I don't give a crap if you wave or not. But do it safely if you do.

A few weeks ago my wife and I were driving behind a few bikes. Another bike comes in the other lane and they do the cool wave thing, but the guy in the other lane swerves right toward us, crossing the double yellow. Had to swerve to not crater the asshole. Not worth it if you can't steer one handed.