|P is for Practical|
In the abstract, I'm afraid I'd have to side with the questioner.
Whilst a man of your in-depth experience and knowledge will often be able to divine more context than supplied, and therefore often be correct in answering, "You asked the wrong question!". Every now and then, your divining rod will give you a false twitch with the result that you end up irritating the questioner as much as he has irritated you.
As a questioner who sometimes explicitly removes the context from my questions deliberately, in order that I may seek answers that move beyond, around or under received wisdom on a particular point or subject, I don't mind receiving the answer. "Wrong question!" if comes with at least a little context of it's own. Ie. Why is it the wrong question. As a quite young man, I got really miffed by parents, teachers etc. that would answer "why?" with "Because I say so!" or "Because that's how it's done!". At 7, I got into trouble for walking 2 miles each way to the local library in order to read books on electricity. (Anyone remember Bibani book?). Of course, it was a good few years before I began to understand them, but I did so hate being told, "You wouldn't understand".
The problem with this medium (web) and email, is that unless you're personally or professionally aquainted with the questioner, you can never be quite sure who you are talking to, or what level of knowledge, expertise or understanding they may have. If James Watt, Benjamin Franklin, Thomas Edison or Einstein hadn't questioned the current thinking of their day, many things we now teach in high school, and take for granted every day, would not be around, including in their case, the computers we are using to communicate. Likewise, Mr. Wall questioned the wisdom of C, shell scripts etc. You, must have said "there must be a better way" to yourself before you came up with the ST? Every new thing comes out of questioning the status quo, and sometimes that means making a mental leap a step beyond current expert opinion.
Of course, I've no way of knowing how much if any of this can be applied to the facts of the particular case you cite, and I have no doubt at all that in 99/100 cases, the questioner really is lagging behind the experts (or even the simply accustomed) in knowledge, but even then, it's sometimes better to learn by making your own mistakes than having to take things as read.
It doesn't usually take that much longer to type "That's the wrong question because <10 words of explaination or pointer to same>". And it's always worth keeping an open mind that, just maybe, this questioner has asked/phrased his question in a particular way because he thinks he sees something new, different, unique. 99/100 times he will be wrong, but it's the 1% that makes life interesting. Engaging in a litte open-minded debate may just lead to something worthwhile.
Examine what is said, not who speaks.
The 7th Rule of perl club is -- pearl clubs are easily damaged. Use a diamond club instead.