Yes, definitely. But it is cheaper to have sufficient admins to manage 100 VM instances, than sufficient admins to manage 100 VM instances plus the underlying 20 physical servers and 3 switches and 2 routers and 2 firewalls and storage arrays and...

I always found beyond a certain scale that AWS was not cheaper, but lately I am questioning even that. Next client who is considering going public cloud, I will need to redo my spreadsheets.