Whippersnappers and their dubya-dubya-dubya's. Reddit is nothing but a glorified Usenet!

And the internet is nothing more then a digital version of a book ;)

I wish books didnt insult me for liking other books

Three things. (1) User identity. (2) Moderation. (3) Storage and bandwidth. If you don't mind using different identities across subreddits, or are fine using some OIDC provider, you can replace a subreddit with something like a phpbb installation, a classical forum. Its moderation tools, while somehow different, should be adequate to thwart spam and whip rule-breakers into shape. Running somethig picture-heavy, even 1/10 of r/pic, would cost considerable money though.