So where do you stand? Are you excited that both Android and iOS will natively support system-wide dark mode? Or are you like me, and you really couldn't care less about system-wide dark modes as long as the apps you use have an automatic dark mode?
I love dark themes for all apps, and have switched all individual apps to a dark theme as soon as it became available (Google News and YouTube very early on, now Calendar and Keep, probably some others along the way).
I like the general idea of Material Design to have much whitespace and some bright colors to draw attention to UI elements. However, when all of that whitespace is actually bright white, and all the colors are highly saturated, and there's not even much in terms of drop shadow or borders to break this up (even worse in Google's variant of MD than in the general definition), then I have better things to do than have my retinas burned out all day. :D
You are right, dark-themed apps just don't look as fun as their light-themed alternatives - the colors of the Google Calendar widget on my home screen really look off - but at the same time, it is much more readable for me, and I wouldn't want to switch back.
For me, a system-wide dark mode would just be easier to handle, because I plan on having all my apps in dark mode, anyway.