Often it is, because the (sic) is placed immediately after the error.
I don't see its use as implying a reprimand in any way - it's simply there to let the reader know it wasn't the writer's typo, but a literal transcription from the original. It's actually less of a reprimand than changing the original writer's word or words. If you quote a passage that was written by someone else you MUST use that person's original text; if you don't it's not a valid quotation.
Stuartli, I agree with you 100%. Generally in my personal experience the only people who insert sic when quoting on an online forum are doing so to highlight the poor spelling of the person they wish to argue with, and at the same time take the high ground by sticking the knife in at the same time.
Hence my name after seeing sic used one to many times by a certain forum editor who if he thought about it for more than a nanosecond or two, would see who it makes look silly.