I’ve seen the following analogy around the fed a number of times:
“If someone posts something, don’t just reply. A post is like someone having a conversation in a pub. If you the rock up and interject with your opinion, it’s rude. Don’t do that.”
That analogy holds no water to me. The post is public so therefore it’s more akin to a town cryer than a conversation in a public setting. Isn’t it?
If you want a conversation with specific people, use DM. If it’s public, it’s fair game IMO.