Krias Kesubah used to be given to the Shammos of the shul. That changed after a famous story where there was a Chasuna with many Gedolim in attendance including R’Moshe Feinstein Z”l. He realized that there wouldnt be enough Kibudim to give to everyone & so he told the Baal Simcha to give him the Krias Kesubah. When people saw him have Krias Kesubah they just assumed that it was a big Kibbud, & so they started copying it.
