Who in this era ...
... thought that launching a communications service without a capable bozo filter with user defined rules was a good idea? What were they thinking?
Collaboration site Keybase, once touted for its encrypted meetup channels and robust developer features, is struggling to ward off an epidemic of harassment and spam brought about by its shift toward cryptocurrency. Longtime users of the site who spoke with The Register have complained that Keybase, a multi-platform secure …
Skype? That's modern. We were swapping killfile entries on BBSes by the late 1970s. Certainly by the time USENET became popular they were common (see Larry Wall's rn, from 1984). Pournelle lamented the lack of killfiles in BIX in his The User's Column (later became Computing at Chaos Manor) in the early 1980s.
Yes, rn and its successors such as nn and xrn really set the standard for killfile capabilities. Quick and basic options for non-technical users, full field-specific regexes for technical ones, transient or persistent, human-readable, editable...
But I think that was part of Pascal's point. This is a well-understood problem, and the consequences of failing to deal with it had been demonstrated in more-recent messaging services such as Skype. So both positive and negative examples are amply available to people designing such services.
(Though, frankly, I have to say that while I've never used Keybase, from the description I don't see what it would give me that I'd want. Currently I have two officially supported and recommended messaging / chat services here at work, and neither of them is as good as Usenet plus IRC, for any use case I have. On the other hand, they consume vast amounts of resources.)
"Social networks can probably survive organic growth. But VC funding in particular drives strong incentive to grow at all costs. ALL costs."
If you let the spammers in, the legitimate users will move elsewhere, and when the legitimate users leave, the spammers will no longer have a reason to be there, so they will leave as well, leaving you with a derelict wasteland.