I am almost convinced with the article but then it goes too far in trying to convince me how sucky it is. Seems a bit pretentious after a while.
One part is the nitty gritties and the other is the experience. I use the app on a daily basis and experientially it scores high with a few hiccups in search and navigation.
I also understand the rationale of using large fonts. Think of using the app when driving a car, playing a sport, running, etc which I think are pretty important scenarios. A larger everything is definitely a better affordance than tiny pretty designs.
When the author mentions the discrepancy in blurred surfaces vs opaque ones, I think a basic rationale is that temporary surfaces have a blurred translucency while permanent surfaces have full opacity. There would be many such core principles that the article fails to address and looks only at how it appears rather than the experience.