It's easy to say and pretty much easy to do. For the average user, the catalog of applications available is good enough - except you want to use some really complex/professional software. "Only Windows" application are mainly commercial, I guess? For Open Source/FOSS/Free Software there is absolutely no reason to be "only for Windows" + developing software is easier on Linux, as Windows has a different and closed-sourced architecture. This "only Windows" (for non-Microsft apps) hype has its roots in the facts, that Windows has monopole about OSes and because of that, it's not lucrative enough for a company to code complex (maybe paid) software for a minor user group - even if they do, mostly OS X comes before Linux. Also Windows hold an even stronger monopole speaking of working-environments in businesses - Yes, for most employees it's not an option to switch to another OS, as software they must work with is supported only on Windows. Nevertheless, some average employee doesn't have even the choice to decide about using Windows or not - if Windows (OEM) is on the working computer, than Windows will be on the working computer, privacy issues up or down - except for those paranoid corporations with ultra-secret business secrets - only there the change is needed (although why would they use Windows in first place - even XP, Vista, 7, 8, 8.1 tracked some statistical data and had the possibility to catch some more). But this doesn't mean that an average person at his/her home with his/her PC cannot switch to Linux/BSD - yes, it requires some time to get in with something other than Windows but it's certainly possible and an option. For most people, it's not an option.
For the workplace, it is not an option for most people. But for the home user, it is very much an option.
For anyone who likes mainstream AAA gaming titles Linux is sadly not an option yet.
Steam has a lot of games that run great on PCBSD under Wine.
In my opinion - forget about privacy when using commercial products. For sure, you can "disable" the ad-tracking-ID in Settings but the big question is: "Does it really helps?" Nope. It doesn't. Turning privacy intruding settings to "off" is merely giving a false sense of security - "I turned it off, and because I trust Microsoft and - more importantly - I accepted those Privacy Policy and Terms of Service, it's logically for me, that it is disabled." If you distrust Microsoft and it's ToS or Privacy Policy are presenting an issue to you - go for a Linux distro. The possibility that something there is backdoored, spying, etc. is practically seen much lower than by commercial operating systems, like OS X and Windows, as it's Open Source (although this doesn't make it bullet-proof or perfect). But of course, you just won't get that comfort as by using Windows 10. You can't get 100% privacy and 100% comfort. Choose the percentage that suits you. Although sometimes there is a limit for privacy.
Personally, I believe that the maximum privacy possible is about 80% - you can completely secure your machine, but as long as it's connected to the Internet there's at least SOME data that's tracked. Good to know that someone shares my viewpoint, though. Windows isn't designed with privacy in mind - it's designed with functionality and money.
Yup, the problem that average people (so average privacy concerned - like "I don't like that Facebook knows where I'm going Tuesday night but don't care that much, that I would make a change in my habits") - won't change their daily, weekly, monthly habits/life in general because of this. It's too comfortable that somebody would give up known comfort for something like "privacy" (which meaning is mostly unknown for him/her). Of course, a complete isolation of a workstation from any form of network is technically the "best" solution for privacy and security. Just, how many of Internet folks would give Internet completely up? It's a too drastic change in an average privacy concerned person life, that it would really make (short or long term) effect. We just have no real option - leave the censored, manipulated, monitored "Internet" behind and go for a run (BTW, it's also healthy), meet friends (or somebody else) in real life OR accept the mountains of ToS-es and don't comply.
Until there's surveillance in the streets that is.
True. But real-life surveillance much more expensive than controlling Internet backbones, upstream, etc. Although the government has anyway de facto unlimited resources, so in a way, it doesn't really matter out of the privacy aspect - you're just more social with people around you (or maybe not), which can be better than chatting them but seeing them daily.
There's also the issue that people can't stop existing - they can't avoid street surveillance. But then again - people generally accept Skype, e-mail and Facebook as social contact so that may also be hard to give up to some people...
I find this whole thing pretty disturbing. I've been on Linux for years. But I have an xbox one and that has some inklings of privacy issues. The problem I have with all of this is that the majority of people will just accept the defaults without knowing any better.