I know this can be a contentious issue and it seems to be argued every time a team (or its owner) threatens to move the team to another city. By one stretch, I get what you and many others say that taxpayers should not fund privately-owned teams or the stadiums. But OTOH, it is often argued that keeping a major league team in the city brings financial benefits such as jobs in nearby establishments. It also fosters a sense of civic pride.
I'm not saying I support one side or the other. These are just arguments for both sides.