I can understand him being upset, because the guy plays his tail off, and is having a good season. He's part of a group of players we have that are the heart and soul of this team.
I like Hayward, he has more refined skills than Crowder, such as passing, ball handling, and he can create his own shots, all areas where Crowder could use improvement. But on the whole, including defense, Hayward wouldn't be much of a step up.
I'd rather get another big that can control the paint, and rebound.