Blatantly poor grammar detracts from the conversation though, especially for those of us who have taken the time and made the effort to improve our own grammatical standards. We may not be perfect, but we're getting better and would love to help others improve, too... otherwise they and their posts are doomed to remain as much of a joke as a screen door on a battleship.
The corrections are there - If the corrected poster does not care to learn from them, that's their choice, but due to a challenged schooling system and the influence of American television programmes many people are simply unaware of their errors, and most quite happily adopt the correct ways. Posts above clearly demonstrate some interest in things like etymology and the reasons behind when/why it would be 'fewer' and not 'less'.
So yes, Grammar Nazi, but also educator at the same time.