Coach Staley hit it on the head. I'll go one step further and say that if you're predisposed to have full "tear-drop" quad insertions and have the right leverages, then you can build your legs with anything. My gym is filled with all these Japanese guys, most of whom have great leg genetics. I have yet to see any of them do full squats in my gym, yet they all have great leg development.
Then there's me, who full squats and deadlifts all the time, and because of the way I'm set up most of the effect goes to my glutes rather than my quads. (Of course, I have great glutes...) The only variation of squats that really have affected my quads directly are King squats, where the hips break before the knees. But it's tough to use much weight with them.
Anyway, I like squats and feel that they are an absolutely necessary component to a well-rounded leg program. But for good quad development, there are a lot of people who need to supplement with other exercises as well.