I don't mind so much about posting under my full name on the LAA Forum, and I think the rule sets the tone for the forum.
PPRuNe is ultimately, a rumour network with no claims to accredited or even factually accurate content. That sensible piece of advice you've just read on a PPRuNe post could be from an experienced pilot/engineer, or it could be from an armchair mechanic writing from in between his buttocks.
The LAA forum adds academic weight to its content by fully crediting the posts to the writer; some of this content goes into the LAA Magazine. The forum is somewhat stagnant, but I think that is purely because the majority of members don't have anything of solid value to write about.
Personally, I have a greater issue with the CAA who happily post my aircraft registration details, full name and address onto the public domain without seeking my permission. The DVLA aren't so free with information, so why are the CAA?