For two, declaring rules and then declaring that no-one is allowed to talk about said rules sets a very dangerous precedent.
For three, pretty darn ironic that both this and http://deathtobullshit.com/ are on the front page at the same time.
It's also easily derived from the values of this site, which are no secret (see https://news.ycombinator.com/item?id=10179248) and have not changed.
It very much reminds me of an ostrich sticking its head in the sand - namely, that the response of a link aggregator to more and more of the links it aggregates disappearing is to say "no it's not, there are <insert increasingly complex and increasingly quasi-legal workarounds here>, now stop complaining".
It's not just now that should be worrying, it's the continuation of the trend. And a website as major as this within its domain is one of the few that has more than a snowball's chance in Hell to divert said trend, assuming it acts in a timely fashion. But this is just waiting around like a lobster in a pot of water being slowly heated.
Also, the reason why said discussions are starting to "choke other threads like weeds" is because it is rather hard to have a discussion about something when one has to resort to increasingly-complex and quasi-legal methods (if not downright illegal in some places) just to read the content people are trying to have a discussion about.