As far as sports gambling is concerned, there is always the possibility of corrupting the athletes, umpires and other officials. While a professional athlete who is well paid would have a lot to lose (just ask Pete Rose) making the pros less vulnerable, the student athlete is much more vulnerable and you have to wonder about the officials sometimes.
There are studies that show college athletes have bet with bookmakers with significant amounts of money on the line. More than 5% of male athletes in one survey admitted to betting on a game in which they participated. They have admitted providing information for gambling purposes and some even took money to try to fix games by playing poorly. This has been documented and people have gone to jail. Obviously this is not good and shouldn’t be tolerated.
The cops are part of our government and the government picks and chooses what it is going to demonize. There are some legitimate concerns however. Some will tell you that sports gambling is not a victimless crime. For one thing, people are making a lot of untaxed money. There are untold millions being bet with no tax being collected. The government doesn’t like this.