Santa clause is obese yes, but has never been depicted as being less of a man for it. Santa also has never been depicted as someone who exploits children. The santa claus legend is largely unchanged and has never been offensive to anyone ever.
SinterKlaas used to be depicted as a person who conquered devils who were in the form of black people, enslaved them to do his bidding, children were made to be afraid of them if they were bad because they would either beat them or steal them away to Spain.
Many people say to me that this is how the tradition used to be but its not like that any more. The thing is that some of these ideas still exist today in the minds of some dutch. As evidenced by the Sketch comedy I linked to earlier of the dutch family having a zwarte piet that was like a slave for them. If the idea that zwarte piet as slaves didn't exist then this sketch comedy skit would not exist. That is simply one instance of the ideas of old making it into society today. Who knows what others there are. Also despite things changing dramatically, zwarte piet are still to this day shown as lessor than the White guy who gets to ride the horse.
Kids make associations all the time.
Kids in America still to this day have some sort of understanding that people of dark complexion are lessor. **LINK** And That is without having this sort of tradition which enforces that idea. Who knows what kids in Holland think?
We are just asking that the tradition simply be made more sensitive to the malleable minds that its targeting. Instead of having ONLY black piets why not let zwarte piet be any color or a range of colors. Or maybe mix up the hair. Its really the clothes that make the Piet anyways.