I don't need my bed to transmit measurements to a server. I need my bed to be comfortable to sleep on. I need exactly zero interactions with a server for that.

So, yeah, back to the question. Why does my bed have an SSH server? Because it needs to be able to talk to some machine on the internet. And why does my bed need that? It's a bed.

[Edit: Wait a minute. Even if I do want to transmit measurements, why is my bed running a server? My bed should be running a client.]