Squats are good because they stress bigger group of muscles, but of course they are more difficult to do and need very proper technique. Adult cyclist should be able to squat say 1,5 x own weight 1-3 times or leg press about 3 x own weight 1-3 times. Better to stay at 0-10 reps as more is useless twitching with legspeeds that one does (hopefully) not use when biking. It's quite hard to say how person benefits from squats as one may win with better aerobic engine and one may lose with lousy power. Balance my friends..balance
Saw and have a talk with C. Sauser this season..opened my eyes pretty well. So thin and not ripped looking at all. But so unbeliveable with bike. I mean really. Go and see for your own how guys like he do the do and think then what is a main point. How much to do squats or worry how my abs look like? Or how much ride your bike.