except that some automation frameworks rely on inbound ssh access to the machines. ansible would be an example of such a framework, in its default configuration at least.
The goal of the tip is really to stop users SSHing in just to fix that one little thing, so you could still allow your automation frameworks SSH access and just disable it for users.
It can also be useful to SSH into a system to check what's going on with a specific problem. Sometimes weird things happen that you can't always anticipate or automate away.
Userify is awesome for this - disable SSH user accounts at any time and then re-enable when you realize you still need SSH to find out why your instance stopped sending logs!! ;)
It's just a way to stop yourself from cheating and SSHing in just to fix that one thing, instead of automating it.