I never really gave it much thought myself, but I kind of see your point... it's a similar case with myself, for example, I almost always try to give my characters names you don't hear very often, especially for fictional characters (Bethany Crystal would have been THE Bethany had it not been for that Frankel chick), and if not, then I'll give them the name that they look like (ala to me, Steve D'Monster... he just looked like a Steve to me).

You mention the secondary/supporting characters having rather generic names, that may seem true for the most part, however, there are a few exceptions, like Vecita for example... that's a name I don't hear very often, even for Latino characters in other programs.