Consider the following scenario:
A (new) user asks a question that is related to a specific plugin. It may or may not employ core functionality, but is at least borderline, if not entirely, off-topic. It however is not badly phrased and does show some research effort (apart from having ignored the Tour/Help/FAQ).
Regardless, you know the answer and could help the OP without much effort or researching. It's an easy type up.

Pro for answering:
Humanity. Altruism. The want to help.

Con of answering:
It would encourage further questions of the kind, by the same or another user.

Specific example, just now: Remove All in One SEO Pack Widget while posting

The OP could have phrased the question more generic. She didn't though. She does show research effort. I could tell her, that she's using the wrong hook. That is (or could be) plugin independent. I left a comment to a question that should point her in the right direction. I did close vote the thing. Still, I could type up a solution quicker than asking for your opinion on meta. I however don't feel like encouraging off-topic content.

What is the right thing to do?