It's important to know one's role.
Don't misunderstand me, if you want to argue Davis deserved to play ahead of Howard, that's a quite reasonable argument to make. Looking from the outside, I'm inclined to agree with you.
But to make that argument that his play has been fine, he just needed to play more is simply not accurate. Up until the last two games, his play was pretty weak.
Given that Crean is very much a "win your minutes in practice" kind of guy, my guess is that his practices were not much better.
The end of the season gives me a lot of hope that he's going to be a contributor going forward.