Fair point but how about this, the board is already famous for sport related discussion. How about renaming the board in a way discussion about sports won't be considered offtopic. Something like Sport/Gambling discussion board. This way gamblers could discuss sport freely at the same time discuss issues surrounding actually gambling. The board is aready seen as a sport hangout board nothing wrong in making it official (just my opinion).
It doesn't matter what it's "famous" for. It famous for spam and discussion that is irrelevant and off topic for there in my opinion. And you can rename it whatever you want but if people are merely just discussing sports in there without any relevance to gambling then it has absolutely no reason to be in Gambling Discussion. If people start talking about films in there then we shouldn't be renaming the board to Films/Sport/Gambling Discussion just because its possible that you can bet on films in some capacity.