I like Star so I'm glad it's getting three seasons. It really sucks that Wander is getting the axe despite the crew more than willing to do a 3rd season. Those Disney bigwigs can be so cruel.
I think Disney has faith in Star simply because of it's ratings. I don't think they are spectacular numbers really but if I recall, the series premiere was one of the best premieres in DXD's history or something like that.