Because most people will just hit the upgrade button because Windows told them to. The majority of people have no knowledge of what MS is doing behind the scenes - nor do they know what Google does behind the scenes when they use Google Search/Gmail/Maps/etc. Most users just use their computers and don't give it a second thought.
And even being in IT I have upgraded a couple of machines - mainly because MS collecting what it does has no real bearing on my life - they can do what they like with it.
I think you will find a lot of people are not just hitting the upgrade button, A lot of people i know are staying put with Windows 7, people who use Windows 8 seems to be the ones who will try Windows 10 and some of them have asked me hopw to get back to Windows 8.
Ms pushing this update have not really had the planned effect, they thought that people would flock to Windows 10 and that have not really happened, I can see the offer being extended to be honest, which is a pain as it means I still need to keep software on my computer to stop the nagging.
I thought people would bring the Google and smart phone argument up. A smart phone is different, you buy a smart phone you know that Google, Apple and even Microsoft with their windows phone is going to collect data, that is how smart phones work. you don't want the data collected then you don't get a smart phone and go for a normal phone.
I have a Android phone, but I don't do anything I think is important on it, I make calls, I receive calls, I send and receive text, I browse the odd website and it is just now and again, I use Facebook, but the info i want people to have which is not much is already on facebook, so it make s little difference. I will take the odd photo. But location is always switched off and I do not write letters or important emails on it.
My computer is a different thing, I browse, I write letters, I do other documents, I send important emails, I got things I think is private stored on it, I do not want Microsoft nosing around my computer.
I also do not want them controlling my computer and installing updates without my say so.
Adrian
Desktop machine now powered by windows 8.1 pro 64bit, no dreaded metro, laptop by Linux
Plusnet FTTC