I for one appreciate the hard work that was Android and Java. I spent two years intensively self-teaching, primarily on Android before starting my developer job. Having to take in large, unwieldy systems with lots of moving parts was mind expanding. I could spend a night in the API, go to bed and wake up feeling smarter.

I haven't done any Android for my job (and just a little Java), but every time I have to design more than a self-contained python script, I'm grateful for the exposure to such complexity.