Well, yes, he's got a massive start over other five year olds in a skill set that will be effectively useless by the time he's say ten and that no five year old is ever actually going to need anyway. That's MUCH more worth his time than learning science or mathematics or economics or a foreign language.
Also, I scoff at the notion that he's not going to ever change his mind between five years old and twenty years old about what he wants to do with his life and will spend all the period in between making sure his specifically Microsoft skills are always up to date. That's
really going to happen. Or he could decide to be a musician or a doctor or a poet or.. a million other things, all of which will mean that teaching him how to configure IPv6 on a windows 2008 server has been an
utter waste of time.
You don't teach five year olds ephemeral vocational skills. It's idiotic.