-Camera software matters as much as camera hardware.

In camera phones the software part matters even more because it is meant to compensate the shortcomings of the mediocre hardware.
When F-Camera became available for N900 and with that the possibility to take RAW pictures, I thought I would finally get the best out of my N900 camera. Wrong. The Nokia camera software was so well fine tuned for the hardware that achieving an equaly pleasing result based on the RAW files was a very hard if not impossible job.

-The same goes for the sound playback of the built in audio card. People complaining Sailfish have a lot of electronic noise in their headphone when playing music.
That is probably another shortcoming of too much hardware cramped tightly in one space.
Maybe noise cancelling-a technique that is very well developped in the mobile phone industry- is not only a matter of filtering noise out of the environment that comes into your microphone but also takes care of filtering out the electronic noise.

Anyway, I think the Sony software 1) matters to get the best out of the hardware 2) is being permanently erased by Sony for those unlocking the bootloader 3) calling it "DRM keys" is just some excuse by Sony to not say we punish you for wanting to try something different not our prescribed way.