To your point about viewpoints: Reddit is pretty demonstrably not a place for all viewpoints. Note that I'm not making a normative comment here, I'm just stating a fact: in most of the mainstream and default subreddits, there are a variety of opinions you really can't express without being downvoted.
As for the thing with the CEO giving drugs to someone in a cabin...I think you should interpret this a little more holistically. For a variety of reasons (starting with illegality, and moving on to liability), that is generally not a thing you want your CEO doing in a well functioning organization of Reddit's size. It's not really about whether or not you're personally okay with recreational drug use. It's a bit of a dog whistle. Things that are generally okay can become very not okay in the context of the workplace and professionalism.
The comment around CEO and drugs was gossip pure and simple and should be ignored. I've seen many CEOs buy beer for employees it is part of many offices. Recreational drugs should be treated in the same manner. I will not judge him any differently.
Each subreddit is a kingdom to itself but the fact that you can start your own kingdom allows free speech without forcing all speech on everyone.
As for the thing with the CEO giving drugs to someone in a cabin...I think you should interpret this a little more holistically. For a variety of reasons (starting with illegality, and moving on to liability), that is generally not a thing you want your CEO doing in a well functioning organization of Reddit's size. It's not really about whether or not you're personally okay with recreational drug use. It's a bit of a dog whistle. Things that are generally okay can become very not okay in the context of the workplace and professionalism.