It possibly could have been a bad batch of 60gig at the manufacturing level, i cant say i have ever heard of it affecting other PS3 version, and its does not seem to be every 60gig, as proven by Watchdog they had 250 complaints that brought the show about and after the show aired nationwide the figure grew to just 600 people complaining of faulty Ps3 with the YLOD, with so little a figure and it being one version of the Ps3 it does seem to point to some manufacturing issue at the time.
Of course that don't help those who are getting the YLOD, no matter how small the number is, and even though Sony were fixing all PS3 for free right up until March of this year which was basically a free two year warrenty for everybody who bought a launch PS3, i still think they should be fixing these YLOD 60gig for free, either that or replace them, but that £130 to fix a faulty YLOD PS3 is a bit much, Sony would have been better keeping the free repaire for the YLOD and the 60gig in my view.