I only agree about two things here:
Tablet Mode is severely unfinished, and;
There are plenty of UI inconsistencies.
However, UI inconsistencies do not affect the integrity nor the performance of the operating system, and--however annoying they may be--will be fixed with time. Besides, the majority of people probably won't notice them anyways until they change to a more consistent design, then they'll be pleasantly surprised. It's human nature to overlook the unimportant things. The things that you claimed were "unfinished" were mostly UI preferences rather than design flaws. That time not so long ago when the Windows Phone Start Screen was just a lot of differently hued Tiles, plenty of people complained about it. People still complain that Microsoft applications such as OneNote don't follow their accent color. I, personally, like the circle profile pictures and understand their purpose, even if you don't. There isn't just the United States and Europe. Windows 10 is for the entire world, and circles for people is less offensive and more culturally accepted in several rather large parts of the world.
I agree that Tablet Mode is unfinished, and I desperately hope that Microsoft will fix it with Threshold 2 this fall. Over all, though, that is the only thing I completely agree with you on.
You act like Windows 10 was supposed to be the only operating system to ever be released already finished and perfect. It has never happened, and never will. Over all, Windows 10 is polished, efficient, and fully operational. Compared to some of the other atrocious OS releases (Vista, anyone?) Windows 10 is as smooth as butter. Now please, stop expecting any operating system to be 100% perfect, and start compromising. You have to meet it somewhere. Either use Windows 10 or don't. Microsoft can't please everyone.