A few flags of mine were declined when I flagged answers that suggest to do things the OP dismissed as not working right in his question. The reason for being declined is the following:
declined - flags should not be used to indicate technical inaccuracies, or an altogether wrong answer
The flag is not about the technical inaccuracies, or that the answer was wrong. It's about it already being mentioned in the question as not possibly an answer. Or do we really consider Y an answer to a question like the following:
I want to do X. I already tried Y but it doesn't work.
IMO, it just isn't an answer and just clogs the tubes with duplicated, wrong content. I don't think posting Y as an answer makes any sense, since it's obvious the user didn't even read the whole question.
As an example, consider the following question:
I cannot reach a certain web page. I already reset my router and switched to a different DNS service, but it didn't help. What can I do?
Now someone comes along and posts either of the following as answer:
Try resetting your router
You could configure a different DNS server, maybe yours has problems right now.
Do we really consider these to be answers? I mean it's right there in the question.
This is not like someone asks for a diagram drawing program for Windows and another users recommends to OmniGraffle. We could tolerate something like this as helping later visitors with a similar issue.
But answers like Y simply repeat what was already stated in the topic and simply don't add anything new to it.