If you fail to understand what the preset rules of engagement and opinions are you're going to have a bad time. Worse still, if you happen to disagree with the general consensus of a sub your opinion will simply be downvoted and your voice will not be heard. You're very unlikely to be educated by existing sub members as to why your opinion is wrong with any real sense of perspective because the hive mind has kicked in and you're not aligned with it.
The larger the sub, the more this problem is exacerbated as there are more people ready and waiting to hit the downvote button. This means that you're very unlikely to encounter a balanced and sensible (aka civil) discussion on Reddit.
Example: /r/@theymos/bitcoin. Now, instead of looking like Reddit's canonical Bitcoin discussion forum, you're reminded that it's just one person's forum at the mercy of one person's agenda.
The obvious problem with that is now stories are filtered based on populist mass appeal, instead of insightful or expert appeal.
Populist content is very different from expert content. Clickbait headline is populist content. A peer-reviewed journal headline is expert content.
Which one do you think is going to be upvoted in a place like Reddit?
the problem with politics is there's not black and white, clear cut right a wrong, but there's a never ending pile of people who insist there is.
True Reddit is decidedly not heavily moderated:
> This subreddit is run by the community. (The moderators just remove spam.)
If you search you can probably find some more subreddits with less general content. And HN is of course a really great website for such discussions, with a lot of highly intelligent people that post quite lenghty comments. HN is probably my favorite website when it comes to discussions.