As a professional author (at least I was for a small part of my life), I know the value of proper white space. Paragraphs are not only a technical aspect of English; they are also part of the art of writing.
(Bleck, the last sentence in that paragraph is not good at all.)
When I submit comments or help requests, I put effort into it to make sure that who ever is on the receiving end can read my question or comment easily. I break up paragraphs by topic, and I even have a closing line.
Thusly (my word of the day), I am irritated when a webform goes and strips newlines from my comment. I also feel sorry for whoever has to read my 4 or so paragraph question, now all strung together into one large and ugly paragraph.
Yes, I realize that stripping newlines is done because it is the trivial solution to a problem. A lot of storage formats consider newlines to be syntaxically significant, and apparently the 50 or so characters in ASCII that are unused are not good candidates for some reason. Mostly newlines are used as a delimiter to make reading a plaintext dump of the data easier, which can make debugging (and other activities) go a bit more smoothly, but this still doesn’t excuse the fact that the result is software that was programmed for the programmer and not for the end users!