Its because they are assholes. Every time I get pulled over the cop is like "the reason I pulled you over is because you weren't wearing a seatbelt". I always end up with a ticket because I tell them its not a law and as an adult I can make decisions for myself.
Well - they probably didn't pull you over for not wearing a seatbelt - but it is the law in most states - including florida - that you have to wear a seatbelt. But why aren't you wearing a seatbelt? It literally makes 0 sense.
On a side note - cops blow