Vinyl records have a mechanical limitation: you cannot put everything as loud as possible on them, else the needle will jump off track.

So mastering for vinyl, even when done digitally, preserves more dynmaic range and finer detail. Ironically, vinyl has a narrower dynamic range than a digital recording, but the "loudness wars" made it use relatively less of that range.

Some people prefer this kind of sound mastering. (Also, the whole ritual and concentration aspect.)