There are different kinds of sessions and sometimes musicians don't realise the effect they are having, but it sounds like these did realise and it was rude. Lets hope that as they get older they will loose the arrogant edge and realise that an open session is not a competition but an opportunity to share music together. Normaly in the folk world even top players are friendly and welkoming and want to hear what others play. We've had great experiences in Ireland.
Come to the Tiger at Beverley festival and there will be several sessions going on at once. You can take your pick.