In my opinion
The chance of having a Triple Crown winner increases interest in the Preakness and Belmont .
When a derby winner passes up the Preakness , that race loses a lot of interest for those that follow the ponies.
The Belmont also is affected, but if the Preakness and Derby winners are in it, the Belmont gains some interest but not as much as if one of the entrants has won two legs of the crown.
The chance of having a Triple Crown winner increases interest in the Preakness and Belmont .
When a derby winner passes up the Preakness , that race loses a lot of interest for those that follow the ponies.
The Belmont also is affected, but if the Preakness and Derby winners are in it, the Belmont gains some interest but not as much as if one of the entrants has won two legs of the crown.