I think posters on Mumsnet in general are getting ruder. I think that's true across Social Media, there's a lot of judgement and rudeness.
However, I stay on Mumsnet for the gardening boards which are lovely, Style and Beauty, money advice, the Christmas bargain threads etc which are all great. When I've been on Tattle some of the stuff I have read about celebrities is downright awful and there have been some really concerning posts that are pretty stalker-ish.
I think if I had a real problem and wanted some advice, I'd be more likely to get true answers here on Mumsnet than on Tattle. Perhaps not all nice, but more realistic than "omg hun" platitudes I see on Tattle a lot.