HN has users from many countries, not just America. And general advice in my country is to wear mask around. Journals share step by step tutorials on how to make them. In some cities, public transport wont allow you in without one (you can improvise with scarf or something). Some stores and pharmacies wont allow you inside without one either. Politicians in photos and personalities wear masks and I think it is to normalize masks wearing. No one here wore mask one month ago, not it is most people outside.

For me it was mind boggling when two days ago HN acted like the smart consensus was "masks do nothing, they are useless and don't wear it".

It is not just "little ad hoc debates". It is also clashing between cultures I guess. There are people down threads actively convincing others not to wear masks and implying you are uneducated if you do. Unless that side of discussion stops spreading it, people who got the "wear masks for others and yourself" advice should be allowed to state their case too.

I dont really know where "dont wear masks" meme is coming from, but it seems to be against everything I hear in my country. Person you are answering to might not be American either.