That's terrible, and not too far off my own experience. When I do manage to shut down Windows 10 without open programs blocking the process, I almost always get a brief flash of a

"Breakpoint exception [hexadecimal error code] ... [something or other]"

dialog box that displays for less than a second. I don't think it shows up in the Event Viewer logs, so if I want to search for the error code online and remedy the problem, I'll have to be quick with a handheld camera.

It could be 3rd party software erroring out, so I guess I won't blame Microsoft for this one until I have more info.