Mudcat's quite an insular space on the web, many of the contributors spend there time here and only here, many of the contributors have also been here for many years likewise. While many fora attract numerous new posters all the time and the turnover can be quite frequent, the membership here stays pretty static. I think part of the reason MC can be as abusive at it is, is because of the old saying 'Familiarity breeds contempt' - the posters here have all 'known' each other for years, and this has diminished the sense of a need to maintain the more formal codes of politeness we would usually maintain with strangers.