I don't see any connection between sports gambling and engaging sport activities. Maybe if those people want to be in competitive athletes in pro level, they are affected by the money that flows in. But otherwise i don't see any connection.

In fact less competitive sports are probably more popular, like jogging and yoga, going to gym and keeping in shape, then sports with teams.

For starters they are harder to organize, gear costs money and they take ton of time. And i am fairly certain that not 1% of the bettors are practicing all the sports they are betting in. They might have some college history, but i doubt it's more than that.