It's not like Teldoserious is unique in that regard. In fact, I'm surprised that the alleged PROFESSIONAL Pilots Rumor Network has no screening process outside of individual airline private sections. The result is posers galore.
While 'posers' can present a problem, limiting to actual pilots would seriously limit valuable inputs and different points of view. I make no secret that I'm not a pilot (although I would have liked to be, and nearly was - but that's another story). But I do have 36 plus years experience as an engineer in Boeing Commercial Aircraft - working at one time or another 727, 737, 747, 757, 767, and 777. In short, I know a lot about 'how planes work' (at least Boeing planes), and I'd like to think that knowledge brings something valuable to the discussions. Unfortunately I often have to censor myself, because I know things that I'm not allowed to make public. Oftentimes it's considered Boeing proprietary/sensitive, in the case of air safety investigations we can get in big trouble for releasing unauthorized information before the official stuff comes out (e.g. I know stuff about Asiana that I can't repeat).
I also value the pilots input on what we do. I've known and worked with lots of Boeing test pilots over the years - some well known, others not so much - but getting input from the guys (and gals) that fly these planes on a day to day basis has a special value.