If the question is "Is the act of downvoting inherently offensive" the answer is "no." I'm sure downvotes can be used offensively somehow, but it seems to me most users use them to actually indicate a real problem. That is not to say they cast the vote for the right reason, but just that quite often the post does have some palpable problem. That is, whenever I see downvotes gathering on something,
usually it is clear there is a problem. —
rschwieb Sep 11 at 13:21