I was looking at this late answer from a new user. Clearly the user just wanted to follow up on the question, but with no reputation the user cannot comment (as would seem the appropriate method to me).
Is a comment the appropriate method to follow up on an old question, or is there a better way? What should we recommend to this new user?
(I'm operating under the assumption that answering with a question is inappropriate but you may also disagree with that premise.)
We're trying to come up with a way to allow new users just a few comments, allowing them to gain more as their comments remain on the site without being flagged and subsequently removed. You'd start at 1 or 2, then be allowed 3 or 4 per day, then 15 to 20 .. up until you unlocked the feature entirely.
It is frustrating to not be able to leave a helpful comment when what you have to share doesn't quite constitute an answer (most often, you just want to help someone improve an existing answer, or get clarification on a question).
The hurdle here: Our comment moderation tools are abysmal, and new comments don't get that many eyes on them by default. Ideally, we come up with something that doesn't require users to review comments left by users with less than 50 rep. It's an interesting problem and one I think we can solve at all scales that we deal with, but we've got to get these moderation tools sorted before we can tackle that (and other annoying new user restrictions).
Comments are less desirable than answers. So I believe the goal is to encourage participation by providing a good answer as well as discourage comments.
There is a tool to "purge comments" which gives you are idea about how StackExchange values them. =)
Further, we don't really want drive by users, we want people to participate and be a part of the community. If the commenter didn't have an answer, and the OP didn't have the answer, then there isn't any reason to bump the question.
(Yes, I think that question was off topic for a couple of reasons.)
In this case the comment may be appropriate. However allowing users with no rep to comment increases the spam. As comments are not monitered like answers ... ie there is a mechanism to flag a answers as first time or low quality ... and it goes to a review queue to be moderated.
Comments as such do not have that and hence it was though appropriate to stop comments from users with no rep to minimize spam.
There should be a related topic on the meta.se
