If there's a reasonable in-universe explanation, then perhaps they would be out of line, depending on how they're phrased. But often, especially with the sort of questions asked here (at least about seeming discrepancies), any in-universe explanation requires such mental gymnastics and suspension of disbelief that they just won't cut it.
I think the important part for our purposes, as I alluded to above, is how the comment/answer is phrased, and perhaps how quickly it is posted. I personally like the "made of plot" answers, and I don't think too many people are offended by them, even if there are feasible in-universe answers. On the other hand, a comment shortly after the question was posted to the effect that the writers are idiots is not appropriate (if it's strong enough, probably never appropriate). I think an answer (not comment), without fairly strong sources backing it, flatly saying it's writer error/irreconcilable should not be put forward at least for a day or two, to give others a chance to come up with in-universe answers.
So the final take-away message, as so often happens, is "it depends." If there's a comment or answer you feel is overly rude, flag it and see what a mod has to say about it.