"Linux doesn't give me browser choice"
Depends on the 'Linux' (or BSD) distribution you choose and how you install it.
Which I imagine is a similar the the point that is being made above about Windows 10, except that the choice happens more at the 'which distribution' level.
"Oh wait, because they managed to corner a large percentage of the market. Did they do this because their software is crap. No, if it was crap it never would died out years ago, they did it because at times its quite good."
I suspect that the cost of changing from Microsoft products may well be a factor for many of the larger and more complex organisations. Functionality above a threshold plus incumbency is all that is required really, and of course Microsoft will ensure that they meet the threshold as you say. Radical shareholders will pounce on any form of 'gold plating' however so radical large scale re-factoring of code bases may not be on the cards. Perhaps we should celebrate the new Web browser as an example of new code?
Home users are becoming more aware of alternative choices and we shall see how that plays out over the next decade or so. That choice might be exercised at the hardware level though and the software will just be 'what it came with' as always. Hence the importance attached to defaults.
The teenagers I teach are quite comfortable with a variety of devices and interfaces, and this cuts both ways so things could be interesting. A low end touch screen convertible laptop with those Microsoft modern apps installed along with the Office apps and ready to go and with auto-syncing to a low end Lumia phone and cloud backup for 'stuff' might actually go quite well provided MS don't crud it up with clumsy marketing or lots of garbageware on the devices.
Coat icon: Its sunny. Need coffee. No milk in.