I think it's kind of ironic, you are willing to criticize the one person who was willing to be a steward (granted even if he's not good at it). But apparently no one else in the building is willing to be a steward. You'd rather criticize and complain about him, rather then one of you but on your big boy pants and decide to take on the responsibility of being a steward. If that's the case, you folks deserve a bad steward.
I get this story is a little different situation, but I coached my son's basketball team and also my daughters soccer team when they were younger. My first year coaching (basketball) I got some good advice from a friend who also coached before. So on game one where I had some complaints (about the refs, about the number of minutes their kids played etc etc). I told all the parents, I only listen to my assistant coaches and I'm willing to have any and up to ALL of them be my assistant coach. I'll come before practice or stay late after practice talking with my assistant coaches about any subject they wish to talk about. You guessed it. I had no one who wanted to complain volunteer to be an assistant coach.
(PS, I had 11 kids on my basketball team and the parent who did complain, was upset his kid played "barely half the game". I did tell him I've got 11 kids, and this is an equal playing time league, so by you telling me your kid barely played half the game, means I did a good job in giving all the kids equal playing time since each kid should have only played a bit less then half the game.)