I think just SSHing to box and doing deploy is not function of users as you noticed but function of how many devs are working on project. For 1-2 devs manual deploy might be ok, when 3rd comes in, it is time to get rid of any magic that might happen when deploying by hand. Because you know someone will do something special and not document that, when he updates automated deploy he does not have to document or talk with other guys, it is documented in deploy tool.
It's also a function of how many servers you have. If you have to ssh into more than one box to deploy then you should probably have automation, even if you only have an ops team of 1 or 2.
