"But my point is that sometimes the tone of voice.....even if it isn't intended....can discourage many people who might have a lot to offer from putting themselves forward."

I think the real intention of posters doesn't always come across the way that it would for instance in a bar over a pint. You can't see the twinkle in someone's eye hence the reader doesn't always interpret the post as it is meant to be. They might think the post is condescending when it is not meant to be. Short of lacing every line with smiley faces (which I can't imagine anyone wants) then maybe the best idea is if you are unsure if a post is being negative to you or not then give the poster the benefit of the doubt. Initially at least!

On the wider issue of course some posts are insulting. However, and I am not meaning to be complacent here, compared to most elsewhere on the net the posters in here are actually really civil. I used to post in newsgroups. In particular soc.culture.scottish and in the end it just became a joke as the thing was over run by really nasty trolls which chased most of the proper posters away. Likewise just visit youtube and the behaviour on many threads is awful. On here though even the threads where people continually argue with another individual (for example the Keith and Jim threads) are for the most part people putting actual points to each other. Not just filled with insults etc. So I am not being complacent as of course things can deteriorate but we are a long way off that at the moment.