I think the problem is deeper. They put batteries in these devices that cannot handle load the rest of the hardware demands. Their solution is to just slow down the rest of the hardware.

I've got a phone that is nowhere near to needing a new battery. It holds 87% of its original charge capacity. Yet it never runs above 50% speed unless it is above 97% charged, and even then it only runs at 2/3rds original speed.