I have worked with Linux for years. I think my first official distribution was Redhat 5.2. In fact, I had telnetted into a local oursc server for years to IRC with buddies or play treksims, or things of the like. When I got into college, or right before (the memory is a little fuzzy) I got Redhat 5.2 Ordered it and everything. :p
I remember the days of trying to force an install and heaven help you if you tried to change any hardware after your custom kernel. That was sometimes a nightmare.
I have two odd issues. I agree with most of what you say. Though I would never admit to "because I like pain," I always said, "Because it's a better and more cost effective choice, duh!" I have Libre office for a lot of things. I tutor kids, and when I say kids I mean college students. There are many times I have to be careful about revisions to papers or notes. (Especially if they are on the other side of the country from me) on formatting from my Open or Libre Office. Both don't quite stack up, especially where inserting pictures in a particular place in a document go. But I don't want to pay some stupid subscription to Microsoft for a program I should be able to purchase once and..... well enough of the rhetoric. Still not a reason to keep windows but to be careful.
My one reason to keep Windows is gaming. I often buy games, or game bundles specifically if they have Linux support to try and encourage individuals to keep that support going. Even if sometimes it's defaulting to side scrollers. I enjoy some of the high def, high end games to play around with: Like Elite Dangerous and World of Warcraft, competitive StarCraft2, etc.
However, much like you in almost all other aspect I have Linux or a BSD up on one machine or another. My stepfather uses Linux for everything he does now. My mother, if she was more tech savvy (and she's not) would have about the same difficulties in windows as linux. I've sat many people down at one of the computers in my house and they were able to do just about anything they wanted to on it.
I have multiple computers in the house. I have two machines with Windows on them. Two. One guest gaming machine. My main box. The only reason I can give, because the majority of the applications I use on a daily basis are open source in one variety or another, is gaming. I take several mini breaks in my small office at the house where I have to perform seemingly hundreds of things at once at any given minute. Those mini breaks might be taking a couple minutes to check out something in a game. (Finding that place in the universe I haven't found yet, or Checking on my dailies to see what's up, or playing a Co-op in SC2)
The VM's generally don't run as fast. Though I have VM's on my main box, and several other Linux machines of various distrobutions around me. Hell I have a huge Thor v.2 that's got a nice AM4 in it, and even a Nvidia HD (though that's always going to take some tweaking). It's just going to take me getting some time out of the three jobs I work to be able to bring it online.
Still I find myself regularly connecting via SSH and X-windows to redirect a display window across my internal network (and sometimes at work) to use the Linux program I want, or access the data I've been working on, on my secure home system.
So, I think some of it drops down to time. Time to work out the kinks. And games. Though I've heard that you might be able to do a seperate steambox and broadcast some of the games that way as an intermediary and have it play on your main linux desktop as a stream option of some sort, I've not gotten the time to play with it or know it's specifics. Though gaming (and specific gaming) is some of the main reasons my main machine is not Linux. Though every machine in my house but my main gaming rig, and the guest gaming rig are Linux. I don't even bother explaining to people anymore why none of the others have windows on it. Nor why I always have a textbox (terminal) with strange letters and a black screen running in the corner of one of my machines.
I don't work in open source but I am regularly an advocate. Whether it's introducing new people in the family to old games. Kids to old console's running in an emulator, or letting them do research for their school stuff on one of my box's it's usually with linux. Several distrobutions and DE's to choose from. Fedora Server with GNOME on one machine (Reliant) Linux Mint with KDE on another (Intrepid) or the older slower laptop with Linux Mint on it (an older version: Runabout.) All still fully functional. When the AM4 comes up it will also be a Fedora machine (Qonos2).
All your other points I find very valid. The gaming thing is a big one for me, and some of the games I've been lobbying for years. Interestingly enough, everytime I try to get one of my other geek/semi-geek friends to swap over to Linux the first question I hear is "Will it run ?" Or will its implementation slow my reaction time.
I always feel it's a bit of a chicken and the egg thing. We need many more super high intensity and popular games ported well to be able to get gaming and video card manufacturer's attention and cooperation.But we can't get those without their full co-operation....etc. Have to have games to get the support to get the games.
For everyday office use, and for work in almost every other aspect of my life it's a linux box I use.