It's not such a mystery, really. People play games to be entertained. A game with potential in a genre you enjoy is less rare than a game at full potential in a genre you enjoy these days, what with all the shovelware on every platform that's poorly designed, poorly coded or both. Something with potential will get patience from its core audience because they have few other options, and a developer releasing a buggy game but patching it afterwards ultimately ends them up with a game at its full potential.

Basically, lots of gamers have a whole helluvalot of patience for the specific games they want, and when the developer is actively fixing problems, they're willing to exercise that patience for the idea that polish will come, even if it's not on release day like it should be.