Our hearing has evolved to listen in a distorted aural environment so that is probably why we like a bit of distortion added?
If you stand in a wood on a windy day and listen to 2 birds in different positions you will still be able to judge where they are (behind, to the side or in front) even though you have lots of other noise around you distorting the sound. The brain compensates and you can make a very good assessment of the sound - millions of years of evolution to get to that point.
Introduce digital (last 40 years?) err brain cannot compute. Alien sound which hearing/brain has not evolved yet to compensate for digital waveform. Yes you can hear a sound but it is not natural analogue so still doesn't sound right.
THE CLOSER DIGITAL GETS TO ANALOGUE THE BETTER IT WILL SOUND. Simple