Agreed. Also, how much more can he learn/improve from another year of junior competition?
Mueller is one of many players who's hurt by the NHL-CHL agreement. He's ready to play in the AHL where he can skate a lot of minutes and in all situations against tougher competition to work on the parts of his game that need improvement.
He probably won't get those kinds of minutes in the NHL, especially offensive minutes and seeing as he's just 19 his game can still improve quite a bit with another year of a lot of tough minutes in Juniors.
If he's ready and the Sharks are going to trust him to skate 18+ minutes a night and use him in more then just ES minutes (as well as give him a long leash) I have no problem with him sticking in SJ.
I know some (maybe many) don't agree but this team is going to be very competitive next year and will be trying to win and if Mueller can help he'll stay, if not he won't.