Yeah, Reddit has been terrible for years (2016 at least) and if you post anything not far left on the more mainline larger subreddits, that is exactly what will happen. If you want more detail on that sort of thing, just browse the r/ShitPoliticsSays subreddit.
Try this reddit site about Star Trek:
https://www.reddit.com/r/DaystromInstitute
You have to have a serious discussion of Star Trek or be blocked.
Serious about a nerdy tv show....
Read their rules on the right side.
Examples:
r/DaystromInstitute Rules
1.
Explain your reasoning
2.
No whinging, jokes, memes, and other shallow content