That's why I said "presumably", and only referring to posting on HN, specifically (i.e. could have had previous accounts).
This is very subjective, but I find people who (again, presumably) haven't been involved in a community who all of a sudden start right off the mark by posting in that community with a phrases like "HN hipsters", to be rude.
"Hipster" is a term commonly used to describe those who advocate so-called "Web 2.0" technologies like Ruby on Rails, JavaScript, HTML5, NoSQL, and so on. These people openly admit that they dislike the previous generation of web development technologies built around languages/platforms like Perl, PHP, and Java.
There are many of those people here, so it makes sense to refer to them collectively, especially given their typical stance toward PHP. Asking them to revisit their current state of PHP is a reasonable enough request.
Now, "hipster" is also often used as a derogatory term, too. It's quite understandable, after dealing with some of those kind of people. But I don't think it was used in that sense in the earlier comment.
I've only seen "hipster" being used in a derogatory way on the Internet. But maybe this is some more HN-specific way that I haven't seen/before, which shows that I'm too inexperienced on here. :}
This is very subjective, but I find people who (again, presumably) haven't been involved in a community who all of a sudden start right off the mark by posting in that community with a phrases like "HN hipsters", to be rude.