There's been a little bit of mention of this below, but I also registered today as a long time reddit user. I was scrolling through instances and seeing sweet Blåhaj made me feel at home. Finding a queer affirming community is difficult on the internet and I was relieved to find a place where that's at the forefront.
It seems that the rate of registration and the technical/moderation upkeep are the correct technical answer, but for my vote, I'd love to see it stay open for a long time.