Like most SE sites, we get quite a few questions that are off-topic or just plain bad. It seems like the most frequent type of offender is the request for a personal equipment recommendation. What I have been seeing is that people still often post answers to these questions, and often the answers are not actually answering OP's (bad) question, but rather explaining why it's bad and/or answering a related question. This doesn't seem like a good practice.
My position is that answers are for answers that answer the question OP asked.
Questions and comments on the question itself should be in comments. If the question should be closed, flag to close. Edit the question if you can improve it yourself. Refer users to the meta or the rules instead of posting long explanations about what's wrong with their question.
For example, see this question. Semi-related meta post: Should I vote up good answers to questions that obviously should be closed?