Is it just my imagination or did I not hear that you wouyldn't/couldn't be stopped solely because of a seat-belt violation? At least that's what I seem to recall when the seat-belt laws were being imposed here in Pennsylvania.
The PA State Police are being very open about seat-belt check points... as are many of the local-yokel Barney Fife types. "Click It or Ticket" ads are running on the radio. And, yet... School buses have NO seat-belts... motorcycle riders don't have to wear helmets... Go figure.
Revenue generation. Pure and simple.