Hey! this board is obviously good for us all - the concentration span continued for quite a long time before diving into the oceanic depths. This may be because both Jackie and I have been away for a while (not together, I hasten to add )

Marty says, "the success of the board carries with it the seeds of its own destruction ." Whilst I agree with the general idea expressed here, I think "destruction" overstates the case.
It is more of a Hegelian thing, surely? - the thesis of this board carries its own antithesis from which, Hegel would argue, something further will be synthesised.
Whether this synthesis will be good or bad, what we want or something else, may not be within our own control. But, insofar as we can control the "progress" of the board, I think the "rules of engagement" that Jo kindly disinterred for us provide a suitable array of knobs and levers.

I have been contributing for only a few weeks, and have no experience of contributing to other boards, but I have found on this board, like so many others who have responded to this thread, great stimulation, much information and endless laughter as well as some rewarding private correspondence.
I am amazed that anyone can find this ambience threatening - it is quite the reverse I would have thought. Certainly there is a core of contributers who form a "backbone," but they are welcoming and tend to be kind to newcomers until they find their feet, reserving the slings and arrows for tried and trusted friends whom they know can take it (and give it back with interest )
It is much like an Irish country pub, where the regulars all chat to each other, but welcome a stranger, talk and listen to him (and even her, these days!) and draw them into the conversation.

Long may it continue - adapting as it must to new members, new ideas and mores and changes in culture.