Earlier quoted context omitted.
In my experience, you get out of reddit what you put in. With an account you can unsubscribe from specific subreddits, which I have done to clean up my feed from angry/creepy/violent stuff and I get posts that I am very interested in, primarily from smaller subreddits about hobbies, sports, cool technology, etc.
I have an account, and am unsubscribed from subreddits I do not like. There's no way to visit /r/all without seeing all the political hate, creepypasta, and violence.
And I'm a user who sometimes seeks drama, that is, r/subredditdrama is one of my guilty pleasures. And I still don't get much of a toxic vibe.
That said, I also don't check r/programming very often. The discussions there seem much more blowhard than their equivalent threads on HN. So in other words, there already is a decent alternative to Reddit: HN. Twitter is also pretty decent.