Windows is taught in schools because it IS the only OS you NEED to learn and use. Sure if you get into the business you MIGHT wind up in front of a different OS, but only a small percentage of the kids will wind up in the business, and thanks to Windows’ dominance most of the jobs in the business are on Windows, if they go to a non-Windows shop they can learn it there (really once you’ve been around a while you learn an OS is an OS is an OS, specific commands might change but the core concepts have remained the same for a long time on many platforms). Kind of like how they don’t teach kids how to drive in right hand cars, because in America they don’t need to know unless they get a job with the Post Office or travel to a handful of countries, in which case they can figure it out there.
Engineers and scientists must learn and use UNIX. Its operation, at its heart command-line based, is very different from Windows.
Define "NEED". We didn't "need" to go to the moon or invent cures for diseases, strictly speaking, but we did because we have a desire for innovation and excellence.
Windows is the minimum. It's the floor, the bottom.
If we want to produce engineers and scientists, we need to teach Linux. Students need to know how their computers work and how to manipulate them.
If we want to produce critical thinkers, we should encourage the use of operating systems which require critical thinking and problem solving.