This is, if anything, the opposite. "I got mine" is when people pull the ladder up after them, e.g. going to the government to pass rules restricting housing co

This is, if anything, the opposite. "I got mine" is when people pull the ladder up after them, e.g. going to the government to pass rules restricting housing construction after they've bought a house and are now interested in raising housing prices through scarcity rather than housing affordability, or the AARP securing healthcare subsidies for affluent retirees by taxing the working poor. It's not obvious how the notion is even relevant to sports betting. The analogous thing would be if some group had made a lot of money betting on sports and then wants to stop anyone else from doing it, but making a lot of money from gambling is not the common case and the libertarian position wouldn't be to stop anybody from doing it regardless.