07:30
On the other hand, just reading this it seems like once again the SFF meta community is complaining about an "outsider" coming in with a complaint. I happen to agree with @Trish that answers in comments are actively harmful. If you disagree, you disagree, but argue that point rationally instead of falling back on "you're new and haven't learned the way we do it".
3
Answers posted as comments:
This means that the only way to counteract incorrect information posted as an answer-comment is by adding another comment, which will almost inevitably lead to a discussion happening on the question itself, when the discussion is about an "answer", not the question.
* are misleading to people not as familiar with the SE system
When you Google a question and come across a SE question, and you see that people are posting things that answer the question in the comment section, that is actively harmful to any attempt made towards teaching people that SE is not a typical internet forum, where people just... post responses to the original post. If there's no clear distinction between answers and comments, new users will inevitably think that they are interchangeable / may not even realize there's a difference.
* subvert the reputation system
You can't get rep from a comment and you can't lose rep from a comment. This means that when you post an answer as a comment, you are not only missing out on the upvotes if it's a good answer, this is providing a way for people to provide sub-standard answers (or incorrect answers) without worrying about being downvoted. This is bad for site health and the reputation of the site, if people can provide bad answers without getting downvoted. Downvotes are an integral part of the quality system.
Comments don't show up in site search for a reason: They're not supposed to contain anything important for very long. Anything relevant should be edited into the question (or, for comments on an answer, the answer). If there's an answer in a comment that's not provided in an actual answer, that means that people who want to find this answer for whatever reason will have a very hard time doing so.
Part of what makes the SE system work is that posts can be edited to improve them, either by the OP or... anyone else. This is also an integral part of maintaining high-quality content. When things can't be edited, that means we lose that integral part of our quality control.
If an answer in the comments provides a satisfactory answer for the OP, the OP has no way of accepting this "answer"... because it's not an answer, it's a comment. This is detrimental to both the asker and answerer - they both lose out on rep; and this also is harmful for story-ID questions.
* push other things down on the page
This can include other comments which are using comments as they are intended - asking for clarification / more details or suggesting improvement - or the people who took the time to use the site as intended and write a proper answer.
People say that comments are a good place to put things that they don't have the time or inclination to make an actual answer. If that's the case, wait until you can post it. Questions don't need an immediate answer. It's not worth subverting the entire reason that SO/SE was created - to avoid forum-like discussions - to get that half-baked idea out quickly. Just wait until either you can write a full answer, or, maybe, let someone else answer.
It's kinda big-headed to go "Only I can answer this question. Nobody else could possibly know the answer to this question. But I don't have the time right now, so I'll just slap together a half-baked answer and put it into a comment to avoid downvotes." Because, really... it is extremely rare that only a single person would be able to provide an answer to a question here.