A "properly administered" Windows OS is no more secure or non-secure than any of other popular OS's being used today. Windows just presents a bigger footprint. Windows biggest weaknesses can be attributed to inept system administration, sloppy security patch procedures, bad user account setup, social engineering, and poor firewall administration. These same weaknesses also apply to all of the other OS's being used today. And unfortunately ditching Windows would also mean ditching all the programs running on the system. Other OS's provide some of the applications being run on Windows so your average user might adjust to the transition. However, all the businesses running internally developed custom Windows applications will not be keen on having to re-build all those applications to run on another platform.
"Don't run the most vulnerable software, it does not matter if it is "industry standard". And what if this vulnerable software is the only option? I am forced to work with a 3rd party PLC interface library the could be vulnerable but there is no other choice available that meets my criteria.
You can build a secure OS of any flavor and then have it fall apart as soon as administrators, developers, and support staff start using it. And enough with the "sheep" BS. Your almost out of puberty so put a lid on your arrogance and realize being OS agnostic will serve you well when you get your first job in a couple of years.