The only people you find complaining on Bitcointalk for the most part are competitors or known trolls like Entropy, Bicknellski, etc...
To answer your question though: No there is nothing valid they bring to the table that qualifies as a scam. Just angry butt hurt trolls who can't stand the fact that all their idiotic "predictions" and false claims turned out to be lies and they are exposed for what they are. So they try to flood the threads and forum with more junk in hopes that people will forget.
This sounds almost like the crooks at Black Arrow who told the media that I work for an ASIC manufacturer as the reason for deleting my posts. The reporter was in the middle of browsing the thread for his story when BA fired up their auto-deletion bot on my posts and other customers who made too much noise; the thread shrank from 420 to 370 pages.