Santa has taken over Christmas
In the celebration of Christmas, I see many people dressed up like Santa....never seen anyone dressed as Jesus
Probably because there are some christians who may take offense to someone dressing up like Jesus.
Think about it, what if Rob Ford decided to dress up like Jesus? Or we could use the local priest or rev. What if your priest decided to dress up like Jesus? It probably depends(like if it was part of an act or simply artistic function of evangelizing) but most probably would not like it if it seemed like they are trivializing their religion.
I think this is why muslims frown on reproducing the image of muhummad. It can become trivialized and even disrespected.