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.
“hi, ancient people here. We learned this lesson hard over many iterations that gambling is bad, we are making a rule that you, future reader shouldn’t gamble or it will also result in your societal debt and likely contribute to your destruction too if you take on too many of the things we learned over millennia and many different civilizations and societies collapsing; and we wrapped it in nice allegories for so it appeals to your innate human proclivity to dream, imagine, and tell stories. Don’t say we didn’t want you!”
Unfortunately it seems our Digital Age civilization is hell bent on emulating its Bronze Age and Tower of Babel compatriots the way we are going.