Not even important. Lots of people (including me) get positive feedback from posting pictures. Positive feedback don't mean jack now that there's no neg rep (not that I'm saying we should bring it back...).
A warning would have been nice, but this is a classifieds thread. Not a thread on whining about being banned.
Was the time-limit adjusted for editing for sale threads? If not, it would be impossible to mark items sold in a group thread.