It's the stack they understand the most so they appreciate the advantages and limitations of said stack. For example I know Linux far more than Windows, to the

It's the stack they understand the most so they appreciate the advantages and limitations of said stack. For example I know Linux far more than Windows, to the point where I can administer Linux and the security policies, firewalls, etc. If I need to connect to a wi-fi hotspot "anonymously" I know how to scramble the MAC address of my laptop's wi-fi interface. I don't even know if that's possible in Windows or not...