But you can ssh into a container. You just need to install sshd and launch it. You also need to create a user and set a password if you want to actually log in

But you can ssh into a container. You just need to install sshd and launch it. You also need to create a user and set a password if you want to actually log in. Why? Because containers aren't a single process. It's a group of processes sharing a namespace. And you can totally use a container as a light-weight VM. While most containers have bash or a your application as pid 1, there is nothing stopping you launching a proper initrd as pid 1 and it will act much like a proper OS. Though, just because you can, doesn't mean you should.