For one, I don't believe this place fosters a hostile environment, although it's definitely a place where people love to tell you how you're technically wrong about something.
For another, I would guess that there are a very limited number of websites that would opt into this sort of anti-traffic behavior. Hacker news could certainly choose to honor it, but it also feels within their right to bypass the block.
I wonder if there's a sort of middle ground, where HN alerts the user of the redirect that would have occurred, but still shoots the user to the desired location.
But now you're getting into user flows and begging the question as to why the redirect is there in the first place.
I'd love to know more about the perceived hostility, even reading up on Mastodon left me with more questions than answers.
It's not really all that much of a moral conundrum. Marcan's belief - expressed a number of times on his Mastodon - appears to be that he can prevent other people from discussing something, for the sole reason he doesn't want it discussed. It's not a particularly defensible position in an open society.
In particular, he is upset that people on Hacker News tend to point out that a contributor on Asahi - Lina - appears to be a computer-generated anime alter ego of Marcan himself.
Me, I have absolutely no problem with Marcan having an anime alter ego, but I don't think it's entirely reasonable to expect people to refrain from noticing this and remarking on it. Marcan disagrees, and this is the source of the HN-Marcan rift.
(As I've remarked before, I do mind OSS projects listing fake contributors, for both ethical and legal reasons, but that's another discussion.)
The problem is more that HN is perceived, with good reason, to be transphobic, and Asahi has several trans developers. This is also the reason why a couple of other people I won't mention don't want HN to link to their projects either, because for every link, several people will bitch in the comments about the validity of their gender and pronouns. (As if creating a web app somehow makes one an authority in biology.)
I mean, obviously, it's not like everybody who comments here takes part in the abuse, but when you spend every damn day of your life seeing it and depending on where you live, possibly being harassed by the government over it too, HN turns out to be one more place where you simply can't have any peace.
(And honestly, even if Lina is a anime alter ego, which you haven't proven, and only suspect, why the fuck do you care? Don't you have something better to spend your time on?)