They have a post on the lemmy.world community which explains this.

Sad to hear, especially at this time of growth. Obviously Beehaw can decide their own path, but for me the values Beehaw stands for have to go hand in hand with federation. Without federation it looses the draw for me. I’ll be over on lemmy.world while this sorts itself out.

I think it’s unfortunately a bad idea for three main reasons (ignoring any practical issues with the terraforming):

• the low gravity can’t be changed, and can’t be ignored.
• the lack of a magnetic field means issues with radiation reaching the surface we’re shielded from
• the combination of these two would lead to any atmosphere we could create needing regular top ups, as it would be erroding constantly.

Did anyone seriously think it would be ready?

This is the one that hurts for me. I guess I’ll have a lot more time on my hands after this month, which isn’t a bad thing.