You haven't understood the term.
I'm obviously not talking about "pre-patching" against zero days. That is impossible.
Zero day exploits ARE generally patched as soon as they are discovered - IF the product is not end of life. If it is end of life, then it will never be patched and will always be vulnerable to that exploit. That is why we patch. That is why Microsoft and Apple are trying to steer you to newer OS versions.
No self-respecting security professional runs an outdated OS except in their lab. Not one. Please listen to people who know the tech.
So listen, I have a computer I've been using as a DVR. It doers hook up to the web, because I haven't logged out of the wi-fi. I used the web to update the program guide But since decided to cut that out, (along with now making you pay for Media Center), do you think I should rush out and put Windows 10 in the machine? I mean maybe a zero day exploit might change the channel on me while it's recording. I'm a skeered o' dat...
I have another computer with XP, I use strictly for searching out "erotic art". Gee whiz, I better get Win 10 on that baby, ASAP.
I mean, what the heck would happen if it got infected? What could I possibly do? Oh wait, I'd reformat it.
Whether you choose to recognize it, or admit it., even free AV programs address, "zero day exploits". In fact, the two I'm using update daily.
You've made it apparent that you know everything to know there is about computer security, and, like a close associate of yours, you have to have the last word.
I don't claim to be, a self respecting security expert", just a hobbyist with good common sense. Windows 10 is garbage, aimed at fortifying M$'s monopoly in the marketplace, along with culling user data, and in conjunction with component manufacturers, introducing planned obsolescence into the hardware aspect of the business..
As soon as 10 was introduced, all of a sudden, every new mobo, and CPU would, "now longer be fully compatible any other OS but Windows 10".
And that amounts to slipping the ring into every user and buyer's nose from that day forward.
You wear it well.