Are they really? RPi is cool and all, but I doubt the market share of ARM development is that big. As I was kid I got interested in programming because I wanted to develop games, and I would guess that still most yungsters want. For that RPi is shitty choice.
It is pretty big for smartphones and tablets. And embedded devices.
Games on smartphones are perfectly viable - RPi is not good enough but oDroid or Google Pixel is.
The only problem is developing on same machine as you use. For that, you need a full fledged, quite powerful ARM laptop. Hacked Chromebook for example.
Otherwise, the emulator is way too slow.
