The case of questions on public boards is different, because those also serve as reference for future people with the same question. Places like SO in particular exist not just to help the person asking, but the countless thousands who will find the question through Google search.

In those cases, if you do the "looking at your context, did you mean Y instead of X" substitution, your answer will be still attached to a "how to X" query, and will frustrate a lot of people who may have a legitimate reason for doing X.