I agree with this. It's like they forget that the majority of the audience are are not really really invested in the show like those of us in fandom are, and so most of the casual fans are just going to be sat there going wtf at jokes about "Sam girls" and "Dean girls" or at fans of the ~book series~ wanting Sam and Dean to sleep together.

It's just so self-indulgent at this point. It's not like there's anything actively bad about most of the meta episodes taken on their own, but looking at it in the contest of the overall series, it doesn't work for me at all. The season 2 episode (Hollywood Babylon was it called?) was actually much funnier to me because, while it did have some inside jokes like the network people asking for more light in the horror scenes, the episode itself is about a film-set that Sam and Dean are visiting. And that sense of removal is crucial to me, and works so much better than Sam and Dean going to a convention with people dressed as past MotW from the series and deconstructing the entire show