Google employee are not allowed to use Windows

I was in Zurich recently and I had the opportunity to visit the Google offices, and I met with a senior engineer who now leads a very important team and I asked him for some advice and I also tried to ask him for some privacy advice, and I was really surprised by the answer he gave me:

Me: "We went around the whole building, we went through the development space and I never saw any machines with Windows, why? …

advice development employee engineer google important machines measure opportunity privacy security space team windows zurich