What would your motivation be, to put an unpopular opinion if there are no means for similar minded people to get in touch with you?
I fully understand that one cannot reveal your real name, or other contact information that is normally used for everyday life, because there can be a backlash that can have a negative impact your life.
They are not trying to get in touch with like minded people, they are just posting comment on HN to share their thoughts and react to a news, pretty much exactly like you are doing.
I will take myself as an example :
1. I think diversity is a completely useless metric. 2. I am in favor legalizing discriminations. 3. I believe we should not help people who want to commit suicide.
I don't consider any of these opinions to be controversial.
Also, I don't really want to talk to like minded people. I already think like myself, and I don't really want a hugbox of people who think like me so we can spend time telling each other things we agree with. I'm interested in challenging my ideas a bit, and encountering new perspectives.
All that said, I use this username on other social networks so if people are determined they can find me that way.