First off, you can find his post here.
I find it rather interesting that he is telling people to put on their "all-growed-up pants" when he is cowering behind "no comments allowed." Probably every blogger has had to deal with abusive comments. I have had trolls on my blog, too. But I don't need to block all comments. I will remove inappropriate comments after the fact. (And no, disagreeing with me does not render a comment inappropriate. Blue language does.)
He is making rather sweeping generalizations about atheists. He did admit to exceptions. However, I do not find any reason to believe that his generalizations are representative of atheists. There exist some people of any belief that will fit his stated generalization.
"Hey, why not call the CARM radio show and debate Matt live on the air?"
Here's a good reason. Someone attempting that is not likely to get heard. Call-in program serve target audiences. And it is, unfortunately, profitable (in the pecuniary sense) to belittle, shout over, disconnect the sound, and otherwise maltreat dissenters.
"By the way, why do you troll Christians most of all?"
I would estimate that it is because christians are the ones who have managed to get their beliefs (to greater and lesser extents) enshrined in the statutes. Christians are seen as a threat because non-christians do not want (for example) legally-enforced, mandatory worship on Sunday's. Anti-gay legislation is apparently supported only by people quoting bible verses.
"Also, if you were truly intelligent, you would consider evidence and arguments that Christians present, or visit Websites of apologetics, instead of squirming and dodging."
Well, I have visited the web sites of apologists. And I have seen a remarkable shortage of evidence. They generally use bible quotes in lieu of evidence. I don't already believe the bible. It's not going to convince me. I have also been banned outright by apologist bloggers who said that people might think my replies were convincing and that they didn't want to deal with them. (I have no reason to believe that this is unique to christians. It is not uncommon for people to want to cripple opposing perspectives.)
Update: I see he has a new profile picture. Personally, I think colorizing an image of the original Doctor Who is just wrong. (I doubt Stormbringer colorized the image himself.) I also don't think the image suits him. He seems (to me) more in keeping with the residents of Skaro.