Look, I don't think it's his fault. I don't think his replacement will be much better. However, I also don't think there's much choice left. The team has lost 9 of 10 games and almost all of them have been blowouts.
What's worse than anything else is that the absolute tank the team has fallen into will destroy any chance of getting a meaningful free agent this off season. The argument for Chicago was always "They have cap space and are better than new jersey or new york", well we're probably not better than New Jersey or New York the way we're playing.
There is no argument for Chicago if they can't boost talent and cap space, because the ownership has a well earned poor reputation when it comes to paying for talent to surround it's players with.
I feel bad for VDN, because I think he did some things well, and the roster hasn't given him much of a chance. However, that being said, when your team is blown out every night by 20-30 points, you simply can't maintain the status quo. The coach is the least expensive guy you can get rid of.
As for what to do in the future, I will have to come up with a new plan. I feel either of my old plans would have been significantly better than what was done (rebuild around Rose, Gordon, Deng, and cap space or trade Rose for Bosh and rebuild around Hinrich, Gordon, Deng, Bosh, Noah).
So the new plan, coming soon, until then, vent away on how badly this team stinks.