The other thing Schwinn bikes are: nostalgic. Yeah, there were Columbias and other makes, but Schwinn was the "it" bike of the 60s and 70s.

Another post on this thread compared them to the old Pinto as a ugly workhorse. I would compare them to the base model Mustang of the 60's.
The Varsity, like the 6 banger auto stick Mustang was made to look like something it was not... a sports car or in the Varsity's case a sports bike.
The base Mustang was slow and it's brakes were over matched by it's weight...
But.. it was new...and it's style was appealing and they made them by the millions and so were relatively cheap.. Ford built them heavy,strong and reliable and marketed them very well so every kid wanted one. In the end they defined the era as did the Varsity.. IMHO