Libel laws in the UK are way more problematic / idiosyncratic than law about "incitement to hatred", which are common (at least in Europe) and made to repress dog whistles.
edit: SLAPP suits are basically legal there, and often used to suppress speech or journalism which would be legitimate and even encouraged elsewhere.
Sorry, I didn't see the "much softer targets" remark but I disagree anyway.
Marketing on HN can be very powerful. The mindshare gain can be enormous. Niches in general are very rewarding if the underlying platform (Google/Facebook/Amazon/Ebay) doesn't deplatform you.
I don't have time to look it up but I'm sure minimaxir (Certified HN Influencer) has made a study on it.
PG remarked on it in What I've Learned from Hacker News[1]:
"But what happened to Reddit won't inevitably happen to HN. There are several local maxima. There can be places that are free for alls and places that are more thoughtful, just as there are in the real world; and people will behave differently depending on which they're in, just as they do in the real world.
I've observed this in the wild. I've seen people cross-posting on Reddit and Hacker News who actually took the trouble to write two versions, a flame for Reddit and a more subdued version for HN."
Anecdata: just today I reactivated an account on a startup I learned about from a Show HN[2]
Edit: oh it's setup like this to cheat on taxes.