In brief, if I'd been in Glark's position I'd have done the same thing. Had the attack gone off as discussed, he would have lost money twice over: his bandwidth charges would have skyrocketed, and the page views (and hence the ad revenue) would have plummeted.
I'm willing to take Fox and ladexter's words that it was not meant seriously, but look at it from Glark's perspective. He sees a largish group of people, some of whom have an ill-hidden grudge against him, plotting to attack his website. Why wouldn't he ban those people? More power to him, I say.
I'll be sticking around. Certainly I'll miss Fox and Brood and the others, just as I miss scully and Ginni and ejg. But people come and go from communities all the time. We lost ejg, but we picked up caltrask55. Ginni left, and truecrystal came. It's the circle of life, sort of.
Back in 1994, I started reading and posting to the AOL Melrose Place bulletin board. It was a tight-knit, snarky forum for discussing the show, much like the best of the TWoP forums. I made a lot of friends on that board, several of whom I'm still in regular contact with eight years later. I suspect the same will happen here. The friendships that were founded on TWoP will continue long after TWoP has been consigned to the dustbin of history.