Is brevity under-valued / underappreciated on HN?

From my experience, more depends on the topic at hand and what sort of crowd it has drawn.

More often a good explanation or answer, is better than a quick answer. Like everything text based, paragraphs help.

Regardless of length, (I do ramble a bit though) I tend to find my early comments in the discussion before any crowd, will get the ire of negative nellys, snowflakes or average run of the mill ... person who doesn't like something I've said or agreed with, which will drown out any upvotes. When there's a lot of comments, I think those who are quick to dislike the general consensus have their attention spread thin.

When reading other's comments, it's about quality, not quantity. There are some comments which are verbose when they don't need to be, and could be more eloquently written, but I'm not some high school English teacher. People are gonna write verbosely and I can't stop them. As for brevity, some comments are thinly veiled snipes at another's writing, others are short for a reason: there's simply nothing else to add, and they're not sniping.