By unfriending you, he just confirmed why you left him. So this is good, you made a good decision. Thank him for confirming that.
I have quite a few ex's including one ex husband, as I am 37. I am friends with all but one of them, a guy a dated for a few years, who wants nothing to do with me. I wonder about that, and I think the issue is likely with him. The rest of them seem to have no issue being my friend, and we all talk fairly often. Heck my husband offered the floor of our hotel room to my ex husband when we'd been out drinking, and he missed his train home, and he did, and we gave him bedding and pillows.
The ex b/f of mine who won't talk to me, is the one with the problem.