That's probably because you've never done anything that's unsupported and unblessed by the chipset vendor.
Use case: rooted American Android phone. Gimped Broadcom radio driver that has FM reception disabled at carrier request, even though the hardware capability is present. Alternate
Use case #2: rooted Sony Android phone. Camera crippled because Sony put the drivers for the advanced low-light and image-enhancement features in ARM TrustZone & throws away the encryption key if you unlock the bootloader via the Sony-blessed method. Acquire leaked files documenting what the code that was hidden away does, and build your own kernel module for the camera that implements everything in normal kernelspace (instead of TrustZone). Post to XDA, then go to bed happy, knowing that you're doing your part to fight The Man and bring Power to the People.