They wanted a barebones, no effort to catch up to top competitor phone, with more practicality, and everyday convenience in mind than putting in 10ghz CPU inside a phone.
We went for a year, and bang... Google probably seen client's PR, and banned Android phones without a superfluous gycoscope/accelerometer/etc stuff. We spent close to year on it.
I was fuming.
Going without a gyro or accelerometer is fine under normal conditions because you've got 2-of-3 so you can synthesize the output from the remaining sensor (my phone had synthetic gyro). But once you lose GPS fix you've lost your last degree-of-freedom and the only remaining sensor is the accelerometer, at which point the system goes into gimbal lock and the platform loses its fix.