Jason Scott, the writer in question, is known for using lots of swears to achieve an emotional effect, but he's excused for that by working really fucking hard on the projects he's chosen to care about. So for me, the context of who he is justifies his swearing, because I know where he's coming from.
As for discarding audience: absolutely get rid of them if you want to! That's the choice of the writer. Maybe I don't want the sort of audience that still gets childjitters when I say the word shit in front of them. I had a professor last semester who told me he didn't approve of my describing another student's project idea as "fucked-up", because it conveyed a lack of respect for the idea. Fact was, the idea was disrespectable—but if I'd used that word, I'd have implied in my politeness some respect for the idea, when in fact I had none.
Jason Scott isn't writing to give constructive criticism. He's writing because he thinks the idea of BluRay needs demolition. In the past, when he's critiqued things, he's shown a restraint of language; this deserved none. (I'll also respond to your manner of responding by saying that I find snarky sarcasm as much of a turn-off as you find my crude mouth, and that I'm much less likely to respect snark than I am swears.)
Not necessarily 'no apparent reason.' Maybe you just don't care if your audience is offended, because people that are so easily offended are people that you don't want as part of your audience. Granted we're talking about people and blogs here, not corporate/startup communications with the public/customers.
If I start talking about my support of gay marriage I immediately offend x% of the population that view gay marriage as some sort of 'affront to God.' I am probably ok with this if I'm in support of something that offends them, but from a company/startup perspective, I probably don't want to talk about gay marriage if it will alienate potential customers and has nothing to do with my underlying business (e.g. it would be appropriate if my business was in selling gay marriage accessories or gay wedding planning services or something).
d) Rather than thinking through what I have to say, I'd rather slip down to the lowest common denominator expression because it's easier, without regard to the large percentage of my audience that may be offended.
e) For me, emotion trumps reason.
f) Has an immediate effect, although not the one I might hope for.
hn is a great place for technically minded people to share ideas on achieving success. Discarding x% of your audience for no apparent reason is hardly a perfect form of anything.