A handful of links on Google with some saying they over volted the card makes it common? Of the thousands (tens of thousands?) who have purchased these cards?
I'm a moderator on NZone, although I rarely moderate these days. When I was active there, I'd have guys tell me "This issue is HUGE! There are 20 guys in this thread who have it! There are some guys on other boards who have it!". Meanwhile, NVIDIA would tell me they'd sold 8,000 of those GPUs so far.
The other things is people would actually create multiple accounts on NZone and on other forums to "report the issue". Remember the big "bad batch of 8800GTs, as told by their reps" scare?
I did IP resolves on a guy whose writing style seemed similar to many others reporting the issue and found he had created over 10 accounts on Nzone to "confirm" the issue he reported. Then I Googled it, found he had done the same sort of thing on several other forums, pointed it out to their forum admins, and got him banned on those sites as well. Before doing any of this I talked to the people at the companies involved and verified the RMAs were in line with other launches and that their reps were not warning people about this issue.
There could be some 570s that have noisey caps in some conditions, maybe even mine and I just don't hear it over their fans and my case fans.
My point is there are people in the world who are really short on what I'd call "a life" and make it their hobby to try and defame/slander NVIDIA, and the anecdotal evidence and "big samples" you see on the internet forums include them in total. (sometimes many times)