I don't see any problem if MK would quietly retire.
No interviews, no nothing... just stop.
He worked hard and achieve everything that he wanted in life.
In music, he played with his heroes, sold millions of records, is considerer one of the world's most influencial guitar players, his music has played on the moon and above all that, there is a dinossaur with his name, LOL.
I agree with Dusty that ODR is a strong album with a 'goodbye' vibe.
Is not good as STP, SL or Privateering but is good in terms on how MK music became. IMO
I think that most of us complain is about how better could be MK appearances. I do not know if Mark played on some NewCastle's events on their stadium (like Sam Felder did). He never brought DS together again (unless when he played a full set on some Land Rover private event) and many other things.
Many of us said that if MK would reunite the old gang together, his solo work would be buried. So we are waiting for some kind of miracle since his concerts got boring at some place around 2008 or so. Wich is normal.