Wishful thinking is not idealism. It is self-indulgence at best and self-exaltation at worst. In either case it is usually at the expense of others. In other words it is the opposite of idealism.
I see 30 to 40 gallery shows a week and no matter what kind of mood I'm in no matter how bad the art is I almost always feel better afterward. I can learn as much from bad art as from good.