Third party software has been available on Linux distributions for a long time all the same.
Shipping this feature out of the box with an OS install started happening only recently (e.g. Night Shift came to iOS only 1 year ago, Windows 10 is getting it just now, AOSP has a "secret" knob to turn it on and it's enabled in 3rd party ROMs, etc).
Shipping this feature out of the box with an OS install started happening only recently (e.g. Night Shift came to iOS only 1 year ago, Windows 10 is getting it just now, AOSP has a "secret" knob to turn it on and it's enabled in 3rd party ROMs, etc).