I've read a lot of "sports writers" and fans write about it's comparable with a soldier going AWOL. It's not.
What he did is, to me at least the same as a guy walking out on his family on Thanksgiving day, right after the Turkey comes out of the oven.
In either scenario there is nothing inherently wrong with giving everyone a fresh start if your heart is no longer in it. But there is a time and a place to take the the drastic action.
If he was done, fine and wish him well. But to just walk out when you know your team and friends you have made since here are playing shorthanded to begin with is just spineless. Hope he has a nice new life though.