Well, I didn't really want to bring this out into the open, but it's there now anyway, so I'll make a few comments which I hope prevent a harmful rumor mill. I'm not emotionally involved, and I hope no one else will get so either.
According to his page on why he left, Hans was "asked" to delete material.
Mike, the forum owner (not me), only asked the two to work out their disagreement offline, by PMs or email rather than in public. That doesn't mean deleting posts (which we can easily do, if necessary). He wasn't taking sides, nor did he have anything personal against either one, and he hoped they would both stay on indefinitely, but said that several members had emailed him about what was going on and asked that it be stopped.
About Hans' statement, "because the owner (Mike Naberezny) allowed a commercial advertisement, completely 6502 off-topic, for the OberonStation":
I always took it to be, as the OP said, an FPGA board for trying 16- and 32-bit variants of Arlet's 6502 coreānot really off-topic. There's nothing wrong with saying on the forum, "I have this gizmo you can buy to make your 65xx adventures more productive, more fun, whatever..." and in fact I've done that with my memory module intended for use with the 65816. I can't even say I've made any net profit on it. So is it a commercial venture? Making money wasn't my goal, although I hoped it would at least pay off the initial investment, and it has (although now I've bought another largish quantity of SRAMs and orders have tapered off). I don't know if it's much different in the OberonStation case.
Then Hans was on a business trip and apparently stayed in a hotel where someone had previously posted spam from so we had banned the IP address, and when he got the "Banned" message, he thought one of us had banned
him. Since he's not familiar with how we handle spam, it's understandable that he would think that. I apologized and I tried to make clear that we never banned him and we hoped he would stay on; but I suppose it was when he got back home (or at least out of that hotel), he started deleting posts.
I'd still be glad if he came back.