Microsoft's major mistake is a simple one...
For the record: even though I'm a vivid and enthusiastic Unix administrator (quite the passionate one at that) I also appreciate and value all the things which you can do in Windows. Although the target audience maybe the illiterate end user there's also a lot of stuff going on underneath the GUI and there's plenty of tinkering and discovering to do.
Please note that I'm not claiming that Windows is without any flaws or issues. But I do think some people don't give it the credit which it deserves. There's a very solid infrastructure underneath (MMC anyone?) and there's plenty of stuff which you can do on the commandline. Starting/stopping a Windows service? No, I don't use services.exe or services.msc for that. I more than often use sc.exe instead (just start it, you'll see what I mean).
But what Microsoft needs to really get into its thick skull is that this isn't the 80's anymore. The market is no longer something you can dictate by throwing (sometimes): horrid stuff at it and expecting people to buy i(n)t(o) anyway because they don't have a choice. Thanks to the power of the Internet; the power of social media and the massive share of knowledge people do have a choice. Worse yet (worse for the vendors): they now also realize as much, or can easily find out with a few mouse clicks.
Yet here we are.. It seems to me that the only thing Microsoft has "learned" from the Windows 8 drama is that this freedom of choice is what got their OS the downfall so what is the logical step to take? Apparently not making your choice of option as appealing as possible, but instead trying to take away that choice of freedom.
Like I mentioned above: this isn't the 80's anymore! I've seen people who were very happy with WIndows 7, even Windows 8, and completely freaked out when Windows 10 happened. Merely because they felt oppressed. They didn't got any choice in the matter, "Big brother" was running their PC and that was a clear sign to them that it was time to try this "Linux thing" and get rid of Windows completely (true story). And the worst part: even though I actually admire Windows and how far Microsoft has come so far I really can't blame those guys. Worse yet: I think they're completely right too.
I'm pretty sure that there are plenty of manages and beancounters and others who actually have studied all this and they know what's good for Microsoft. Bollocks!
PowerShell. That was good for Microsoft, because it actually managed to get talked about on Unix fora where even Unix fanboys (you know, the "I hate Windows because... you can't open it") had to admit that PowerShell "wasn't all that bad".
Mono. That was also good for Microsoft because plenty of players could respect the fact that Microsoft allowed a bunch of fans to hack into their crown jewels (pun intended) and provide .NET on other platforms. Many people enjoy mod-mono (yours truly included) but not only that: got a nice taste of what working with a Microsoft standard was all about.
But everytime Microsoft has something good they feel the need to enforce other stuff on us. Visual Basic 6 anyone? It's EOL is waay behind us, Microsoft opted and pushed heavily on .NET but a large group of programmers remained who won't let VB die out like that. Because VB can get you places where other languages can't, not that easily anyway. Only now has Microsoft finally realized the obvious and they're actually adding the VB dll's to later versions of Windows so that code can run without the missing DLL messages.
So yeah. Microsoft's mistake is that they don't try to appeal to the masses. And when something good hits them then it seems they're even too stupid to realize it. Give people what they want, not what you think they need. What people need is getting what they want. And when done right then giving them what they want could even be good for you Microsoft.
But if you keep this up then I honestly fear for the worst. It would be well deserved, but not something I'd enjoy. Because the less players we have on the IT market the more vulnerable us consumers become to getting even more crap pushed down our throats. Because then we won't have as many choices as we do now.