Why Debian vs any proven UNIX variant that gets the job done.  FWIW, you can change environmental and user configurations in Windows, and just like UNIX - it has its consequences.  That last sentence had me LMFAO "OS that was not designed to manipulate or spy on you".  Sheeple.  Operating systems are DESIGNED to host programmed services.  How you use that, is up to you and the limitations of the operating system you (or others) have selected.  You have the choice to be aware of the services being processed, however ALL systems are susceptible to misuse and abuse by externally introduced and hard-coded malware, intrusion, mis-representation by proxy, and theft.  
I think your point, is that your choice of systems is easier to lock down and prevent unauthorized access than a common windows based system.

There are Windows based systems that are minimally exposed.  Issue is often more that desktop applications like the browser and user introduced services that compromise O/S security that are the source of the threats most users face.  I have had to pull my Debian based systems off-line several times this year from hacks (smtp spam services), and I see that the linux patches keep coming, nearly as fast as Windows.