<p>I think it is incumbent on the more knowledgeable, when they give advice, to also inform the asker when their choices may not be particularly suitable.</p>

<p>It's certainly possible to take the position "I just answered the question as asked", and to an extent, I can sympathize with that, but (to take it to an extreme, in order to illustrate a point) imagine someone goes to the doctor with a question like "which is more likely to lead to an improvement in my sore neck - arsenic or cyanide?". The doctor <em>might</em> simply answer the question (presumably by reasoning that since arsenic should kill you more slowly, your neck might well improve before you died), but most people would regard that as very poor advice from the doctor, and argue that in fact the doctor should focus on pointing out that both those options are extremely bad ideas.</p>

<p>So, somewhere between someone asking a question about an innocuous activity, and someone asking about a dangerous one, there's a large spectrum of more or less inadvisable ones, and there are times when we should be saying so.</p>

<p>It's <em>certainly</em> not our job to try to generate some optimal analysis every time; indeed, often simple (if somewhat suboptimal) analyses - if they contain no dangerous surprises - may be actually good advice.</p>

<p>So we have to figure out where to draw the line and when to say "wait, this may not be such a great idea as is". I'd certainly have mentioned something about the issue in that particular case (if I was answering the question), but given the details of the question (it's for "comprehension purposes") I wouldn't have downvoted your earlier answer (and didn't when I read it). The OP doesn't appear to be attempting inference (tests, CIs, standard errors, etc), so the issue of heteroskedasticity is more about efficiency. I don't think it's necessarily that huge a deal; suitability (or unsuitability) of the model for the mean would worry me more.</p>

<p>So while I wouldn't downvote in your case, there is some further point along the spectrum of questionable actions at which I'd say "actually, that's not good advice"</p>

<p>Ideally someone comments about what the problem is when they think there's a big enough problem to downvote, but it doesn't always happen (and you have no way to know who downvoted you if they don't tell you they did). The best thing you can do is try to understand people's comments and where it makes sense, try to accommodate them. </p>
