The fact is that some people don’t blurt out “answers” willy-nilly, particularly for uncertain questions. They ask a few things of the OP to gauge the their abilities and clarify their needs. This is particularly true on SuperUser where it is common to ask some questions and have the OP perform some steps to determine the current state of the OP’s issue, as well as to offer some steps to lead towards a solution.

For someone (often “low-reppers”) to come along and create an answer by copying what someone suggested in a comment is clearly, as squillman said, “rep-whoring”.

This is particularly true when the question has not even been definitely solved yet. It is one thing if the OP has stated that what someone suggested in a comment solved the problem/answered the question, and yet, the question is still open after several weeks (don’t assume that everybody checks the site 100 times a day), but if the steps that were offered in the comment were just diagnostic steps or requests for clarification/more information, then “answering” it at all is—at best—premature, let alone if it was made with someone else’s information.

(For the record, sometimes this happens legitimately when two people see a question and start typing at the same time. One person types up a comment, the other an answer, each of their own accord. However, there are plenty of occurrences where the “answer” is clearly several minutes later, and is short enough that they cannot make the excuse that they started at the same time but took several minutes to type it.)

The fact is that some people don’t blurt out “answers” willy-nilly, particularly for uncertain questions. They ask a few things of the OP to gauge the their abilities and clarify their needs. This is particularly true on SuperUser where it is common to ask some questions and have the OP perform some steps to determine the current state of the OP’s issue, as well as to offer some steps to lead towards a solution.

For someone (often “low-reppers”) to come along and create an answer by copying what someone suggested in a comment is clearly, as squillman said, “rep-whoring”.

This is particularly true when the question has not even been definitely solved yet. It is one thing if the OP has stated that what someone suggested in a comment solved the problem/answered the question, and yet, the question is still open after several weeks (don’t assume that everybody checks the site 100 times a day), but if the steps that were offered in the comment were just diagnostic steps or requests for clarification/more information, then “answering” it at all is—at best—premature, let alone if it was made with someone else’s information.

I have even seen some people rapidly throw up an answer as soon as possible, sometimes/often copying the steps that others have suggested in comments, in what is fairly clearly an attempt to just get an answer up. They then edit it as more information becomes available. In some cases, the original answer they posted was completely useless and premature (hence the probing questions that others started with); but they posted the answer quickly because they can start getting credit (some people up-vote prematurely too) by changing it to be more applicable later.

(For the record, sometimes this happens legitimately when two people see a question and start typing at the same time. One person types up a comment, the other an answer, each of their own accord. However, there are plenty of occurrences where the “answer” is clearly several minutes later, and is short enough that they cannot make the excuse that they started at the same time but took several minutes to type it.)

In summary, yes, usually it is indeed bad form to copy someone else’s comments into your own answer because the practice is often unnecessary, usually unfair, and often accompanied by other low-brow behaviors.