You assertion is not quite correct. Shark meat is consumed, although I will admit it is not as commonly found in fish markets and supermarkets as other types of fish which are plentiful (at least not in my neck of the woods (LA)). Shark fins get a lot of attention because of the cruelty associated with harvesting them. read more
The fins are worth much more than the meat, so what people are doing is catching the shark, cutting off their fins and letting the fish go, leaving them suffering and eventually dying. There are many places that have recognized this and put a ban to selling meals prepared with sharks fins. Hawaii was the first state in the US to do this. read more