What are you even talking about. The people on beehaw are not trying to pretend that the internet as such is nice. They are creating a community with a specific code of conduct, and that is just as real as any other place on the internet. You can still talk about shitty stuff, and you can have dissent, conflict and discussion on there, nobody pretends that that all doesn't exist. The only requirement is that you approach with respect and well-meaning by default for everyone around, there's nothing else to it. On the contrary, I feel like people who don't want to follow these rules are the ones pretending - pretending that they're not interacting with real people, that anything they say doesn't affect others.

You seem to be under the impression that any "nice" space must be fake, because, I don't know, people are inherently not nice, or something, and thus everyone must be just pretending? That's a pretty sad way to view the world, and absolutely not true in my experience. I know plenty of great places and communities made of people that just genuinely want the best for others by default, both online and offline, and it takes no pretending, it only takes a bit of caution to keep the very few people out that are not there to participate constructively and can't or don't want to clear the pretty low bar of respect and well-meaning.