I'm glad I found this thread.
I have a 2015 Hatch, and I've felt like I've been just demolishing rear brakes for no reason. (My last pair only survived about 12,000 Miles!) A Mazda mechanic once mentioned that the brake system is designed to apply the back brakes first, then the front if needed, which means the back brakes wear down more... but this seems absolutely excessive. Has anyone else heard this (or can anyone confirm if this is really how the brake system works)? Everything else on my 3 has been GREAT, but holy hell the brakes are frustrating!