There are many sub communities within the broader startups and entrepreneurial fields, but what HN used to be was a group of people who were hackers first with interests in stories about other startups, new technology, implementing technology etc.
There is an entire other subculture around working from home, the 4 hour work week, SEO, affiliate marketing, how to ship product online, how to write an ebook that can sell for $40 in 24 hours, the micro-ISV space etc.
That later group, who would prefer to talk about how they sold $50k worth of software or ebooks, is much larger than the group of hacker entrepreneurs who would much rather read about the latest Javascript library, security exploit or scientific breakthrough.
Business of Software, the forum that Joel Spolsky ran for micro-ISV's shut down and it seems everybody came flooding over to HN (or were coming over steadily over the past few years). This means more of that type of content.
There can't be more than a few thousand technical (or want to be technical) entrepreneurs, while the group who are interested in breaking away from their career and becoming an ebook affiliate likely numbers in the millions.
A lot of those negative comments are, I feel, from frustrated hacker entrepreneurs who know you can make $100k a year online and who don't want to hear that story again. I didn't click on any of those links when I saw the headlines (no offense to the authors, but it just doesn't interest me) and the only reason I clicked on this thread is because I couldn't believe that another thread that mentions an amount of money in the title had again made it to the top of HN.
I have gone from clicking on 60-80% of HN headlines to now hitting 10%, on a good day. I bet that if I did click on one of those headlines, that I too would have left a smart-ass cynical comment as well, but i'm passed that stage of protesting submissions that I feel don't belong here and now just move on (except this thread).
edit: I realize that I made some sweeping generalizations, I don't mean that people interested in SEO aren't hacker entrepreneurs, I just needed a way to define what are different groups of people in the audience here.