But that's not true. I know several guys who make a living at it. The casinos don't care because they make their vig on the action. The only losers are the folks on the other side of the bets.
It is true that the casinos will find a way to ban people who find an advantage in traditional games like blackjack (think card counting), but that's different. In sports gambling, the profit is extracted with the vig/spread.