But a much easier argument against sports betting is that it ruins the sports. Players throw. They get good at subtly cheating. The gambling apparatus latches itself to the sport, to the teams and players, the umpires and judges, the sporting organizations. With this much money on the line, it's not a matter of if but when games are thrown, cheated -- the bigger the game, the bigger the incentive. It's even easier now because of the amount of side/parlay betting that is available. It exhausts the spirit of competition.
Sports gambling is diametrically opposed to sport itself.
If that were true, people would stop paying attention of it. What other criterion would you have for the quality of sports?
But the worst is how easily you brush aside that it "ruins lives". Not that that's your fault. It seems that almost nobody cares about it. It has been known for a long time that gambling is detrimental, to individuals and to society, yet a bunch of Wolf-of-Wall-Street-style financiers use it to get richer without the need for as much as a good idea. There's less ingenuity and skill involved in betting than in drugs. It's bottom of the barrel amorality, bribing and corrupting its way into politics.
And nobody cares.