I was reading this Slashdot post about "why use linux" and pointing out all the good things we have.
But really the question applies to pretty much any OS now. A huge percentage of users could be told "you're using X at work" (well, not X, like a variable, $X) and they'd adapt, begin to prefer whatever OS, and buy it for their home computers. [I'm sure Linux would accelerate /fast/ in the case that a couple of major companies start deploying to the desktop (this is gonna be the year...).]
I own 3 Macs, but I'm as or more at home in Linux on the desktop (I didn't "switch" from Windows, I switched from Linux, by accident, and I stand by those words today). I only really use Free Software, even on the Macs, save for a couple of things to be addressed below... When I set up a Mac, the stuff I always set up is:
OwnCloud sync client
And that's about it, and you can run 37% of that functionality on any platform, subbing Pidgin and excluding a decent shell on some platforms (Cygwin doesn't count), which is weighted at 62% of the total functionality of any computer I use.
I use iTunes, Mail.App, and Photos, (which is loathsome), as well as calendaring and contacts, so not all Free Software, but I guess I use "Apple Software and Free Software" when on the Mac, but that's mainly because of aesthetics, not any functional advantage they may or may not have over Free alternatives. Mail.app looks nice, iTunes looks nice, it's nearly impossible to run Amarok on OSX, at least the last time I tried, they integrate well with their OS, etc. However we must be able to run things like Adobe software, and OmniGraffle. I'd hate my job without OmniGraffle.
On Linux, I can do a handful of small things I can't do on OSX, and the same thing the other way 'round. But I set everything up exactly the same. I prefer the OSX Keychain Encrypted Notes function over my GPG encrypted files, but just because it's smoother. OSX has improved in handling multiple monitors over the past few years, and KDE, and X in general, has gotten much worse at it. I like to have multiple screens, with multiple virtual desktops, and when I change virtual desktops, I want only that physical screen space to change. So I have Enlightenment. Easy (enough) and gorgeous, and all kinds of customizable.
Other things are a massive pain, Juniper SSL VPN with a requirement for 32-bit Java and Firefox. Come on everyone... But it works, and I use it day to day. It just took a month to get the machine set up the way I like, and it takes some upkeep when some package gets updated that breaks that arrangement. But it's never been a showstopper, because I'm a professional.
However, even for any non-professional, there are major cases for Linux:
Linux runs my home theatre, which boots to Kodi so I can stream TV and movies from our collection of ripped DVDs, watch online streams from the major networks, PBS, Archive, etc*. Chrome so we can watch local news, use Amazon and Hulu and stuff, and browse seamlessly through emulators for any game I care to play through N64/PS1 era. All controlled by the TV Remote (within Kodi) or any Android tablet or no-provider obsolete shitphone (With KDE Connect, Yay for KDE Connect!). Haven't touched the wireless keyboard in at least a month.
This is all doable on a $35 Raspberry Pi 3 right now. I know that part because of the video game cabinet which is on the horizon and which does exactly all this stuff, including
Wipeout XL PS1 Games. I'm sure we will be doing build blogs on that.
So what about Windows? Not for my specific use cases, but why should anyone care who isn't old and curmudgeonly? I carry grudges maintain baggage from 20 years ago.
I hear there's transparency now kind of, and virtual desktops are finally a thing baked into the OS, but every time I log into my Windows 10 VM at work, I am infuriated by it, so why should I bother? Windows can suck it. That's all I know. I'm happy enough to do server admin of Windows servers, I don't much care either way whether I'm adminning Windows or Linux at the end of the day.
Desktop OS? No dice. How times change.
* Side Note: Please do not buy one of those "pre-built pirate box" Pi's with Kodi and a bunch of janky, buggy, potentially insecure plugins pre-installed. Kodi has very strong feelings about that, and I agree with them on the point that regular people who think this is going to be better than an Amazon Fire stick with Free TV streaming are going to:
A) Be disappointed
B) Bring awful attention to a fantastic project by unfairly associating them with and implying their endorsement of piracy and copyright infringement.
C) Could be setting themselves up to get owned by pre-installed botnets or whatever other backdoor/sniffer/malware nightmare scenario, I can't even imagine buying one of these...
People are of course going to download and use those plugins, but should know what they're doing, not blame Kodi for any fallout, and most importantly should not give money to thieves and scam artists, because that's dumb.