Microsoft engineers badly need to take that UX course IMHO. The way Office 365 UI has been evolving is flat out bad design. For starter, the current tendency to move a bunch of widgets in the titlebar. Yesterday I was working on a Word document. I just wanted to move the window between my two monitors. I had trouble finding a spot where I could click on the titlebar to drag it - it was 80% taken up by shortcuts, the new filename widget, the new search widget and the regular window widget.
The Search bar move to the titlebar was very contested. There was an issue on the MS portal asking for the reversal of that change (I had started a similar request, which was merged into that one). There were a thousands of upvotes in favor of reverting this bad design decision, with a bunch of user feedback explaining why it was a bad UX design (I personally hate having to move my mouse all the way from the message list to that search bar, which used to be right above the message list). The end result? Microsoft replied "we are not reversing that change because we don't want to.". And they locked the issue. Zero rationale to justify their decision...
A titlebar should be limited to showing the title, and providing window management feature. Having application features taking up 80% of the real estate is bad design, because it impairs your ability to do window management.
We could also talk long and hard about more bad UX design decisions within WIndows in general. Or the horrible UX they had implemented for the original Edge (zero visual cue to indicate that there was a user-editable URL field there - you had to click on a flat surface to see a text input bar appear). Or the Windows 2004 start menu change where half of the time that I try to click on the Power icon in the start menu, the menu expand before I can get the popup asking me if I want to restart/shutdown, requiring me to do a second extra mouse click.
This extends to websites in general. Lack of input field validation make for a poor user experience. Here in Canada, our postal codes are in the form of A1A 1A1. Well, some websites will require the space, some will refuse the space, and some will accept both forms.