I think it is a subject that should be brought up. I do not think that a flat-out "stop complaining about it" is the proper response - and, to be frank, it disappoints me that that is the approach you seem to have decided to take.
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.
Oh we probably agree more than disagree about the trend, and it's certainly on-topic for HN in the sense that stories about it and debates about it are welcome here in their own context. Choking other threads like weeds is another matter. We've noticed that becoming more of a problem lately, hence this post.
So is it acceptable to post separate threads about the topic of paywalls, then? Because if so, please make that explicit. At the very least, I did not get that impression, and reading through this thread it would appear I am not alone. And - assuming it is acceptable - how? Ask HN does not seem appropriate. Tell HN does not seem appropriate. HN doesn't generally have discussion threads on their own right. We are being told that other threads are not appropriate. The HN guidelines say "Please don't post on HN to ask or tell us something (e.g. to ask us questions about Y Combinator, or to ask or complain about moderation)." So where is appropriate, then?
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.
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.