I don't mind the mix of app styles these days. I realize it will take a lot of effort for developers to modernize some old applications and there are many old applications that will never be modernized due to disinterest from developers or no active development or too big of a code base.
(I also like that modern apps can run on all my devices, including my phone, as I'm one of the few weird Windows 10 phone owners.)
And yes, this is exactly what "spent trust" is: orders came from On High to take off, nuke the site from orbit, repave with Win7 images, and never ever let Windows Update touch the boxes again (!): MS is now, by executive fiat, considered rogue ("we literally cannot afford another Windows X infection, WU is now an attack vector"). Everybody loses (except for that guy at MS whose bonus hinges on number of finished WinX installs; btw if he's reading this: you are, personally, a reason why we can't have nice things): security is undermined by no more patches, man-months are wasted on getting stuff to work again, there's plenty of MS-directed anger, customers are angry at company, not to mention we won't get WinX anytime soon, if at all. Whether anyone is willing to convince the mgmt that they've overreacted over MS's overeager installer is left as an exercise to the reader.
(The "close-as-yes" is also not "an issue", it is not mere "bad UI" - that is black-hat UX (and oh, very much against MS's own UX guidelines, hello hypocrisy!); deception, plain and simple.)
((The mix of app styles is but a minor quirk; and for really oooold apps, there's Virtual PC anyway.))
I don't attribute that to malice but an honest mistake. I think there was a combination of engineering pride involved ("Why wouldn't people want to upgrade as soon as they could?") and engineering obstinacy ("We don't want another XP!"), perhaps even more than that marketing metric everyone thinks they were focused on.
As for the anecdote of the business outage. My condolences. It sounds like the HW vendor should have done a better job at messaging to Microsoft that their existing hardware driver was not testing compatible with Windows 10 (and maybe a better job at their driver in general). Also, companies had the options to use System Center and Group Policy to drive GWX away, and admittedly that's not an easy admin task, but generally something companies should do for mission critical PCs anyway. (Not to mention that GWX is/was different on Enterprise SKUs and possibly a sign your anecdotal company was using not properly licensed Home or Pro SKUs on mission critical machines.)
Anyway, doesn't matter now if the GWX fiasco was malicious or not. Damage is done.
Windows is a huge ecosystem and there is a lot of blame to pass around in every direction. I admitted that it was an MS problem, but I was also trying to point out that it was an ecosystem problem too. (There hasn't been a major driver architecture change between Vista and 10 and it blows my mind how many drivers needed new releases every Windows version between Vista and 10 and weren't just magically compatible.) Apologies if that point did not come across well.