Onebat, about your point that the only ethical position is not to have started Moldies at all:
I see what you're saying - if there'd been no Moldies, there'd be no hurt feelings - but it's not that simple.
If you (I don't mean you personally by the way, I mean one generally) say that the Moldies webboard shouldn't exist, you're in effect telling people how they can communicate with other people away from Mumsnet.
That has its own ethical implications, about freedom of speech and association. Nobody has the right to control how other people communicate off board.
There would be uproar, for example, if anyone tried to suggest that MN-ers weren't allowed to email, MSN or meet other MN-ers. Yet all of those methods of communication will exclude the majority of MN-ers.
In fact, the exclusion aspect is often the point: people want to talk about things they wouldn't disclose to the whole world, which is what the www effectively is.
It's a difficult problem with no perfect solution, but seeking to control MN-ers individual friendships isn't a viable option either.