KDE 5.4 is much more awesome and it's really for free.
You say Win 10 is free? Not really, we pay Microsoft with our privacy.
Well, the thing is now they actually said it out loud what they are monitoring. Pretty sure they are still monitoring something which can't be disabled and wouldn't be surprised if win7/8 did so as well.
Linux is cute, but the issue is that it is not the mainstream platform so the the number of actually good and quality apps is pretty inferior to Windows (taking games into account). Also, you need to do like an hour research before you can do anything out of ordinary. Eg. I wanted to install JDE so I can run NetBeans, well it took like 5-10 minutes to find a 12 step tutorial on how to actually install it correctly. But yea, as a reward for that, you can be pretty much sure that developers aren't spying on you.