What can you do to prevent going down the rabbit-hole of answering a question where the original poster just doesn't get it?

Questions that seem innocuous or should have a straightforward answer quickly devolve into comments that reveal how big of a mess the OP is really in. And maybe I'm looking for a more graceful way to exit.

Start with this - a disk failure: HP Proliant DL180 G6 - Smart Array P410, bay 11 error

From there, it goes into conflated error messages, YouTube videos, screenshots, firmware, lack of documentation, an explanation of RAID and ends with multiple suggestions to just replace the disk... But wait, how DO I replace the disk? And why is my system with a failed disk performing slowly? And even more tangentially-related fallout.

Is this the state of Professional in 2014?

Or this simple FreeNAS drive failure: zpool status reports error ... what next?

"Replace the disk"

This spawned numerous followup questions (some with great. answers.):

Need to identify disk in zpool ... how?
http://serverfault.com/questions/586847/need-to-replace-disk-in-zpool-confused
http://serverfault.com/questions/586949/freenas-var-write-failed-filesystem-is-full
http://serverfault.com/questions/586952/freenas-swap-pager-i-o-error-pagein-failed

But in the end, looking at this in the context of the poster's history, there was nothing but a disastrous string of bad situations, each linked to the previous. Is there a point where you just give up? If I were an employer or this poster's superior, I would have serious concerns about their ability to solve problems or that they were wasting time with a solution they could not manage effectively.

Or a networking question:

How to use iSCSI MPIO to increase bandwidth with XenServer?

I saw back-and-forth in the comments section. Multiple users tried to explain the flawed logic of the question via comments. One excellent answer was posted, but the OP still wasn't on the same page. I gave a terse explanation describing what the real focus of the issue should have been.

Maybe it was colder than intended, but I notice that a lot more hand-holding is needed in questions that should not require it.

(Sometimes guidance is necessary, but there's a difference between working with someone knowledgable who's in a bind and teaching someone the basics along the way to answering a question)