Because suddenly changing Santa's species won't totally kill the illusion for tons of children... "Gee mom, how come in every movie before 2014 Santa is a human? You always told me he was a penguin, also, the movies all say hes from the North Pole. What gives?" Not to mention all the kids who believe in Santa DURING the transition. Half the time he'll be a penguin, half the time a person. "Hey mom, last year when I sat on Santa's lap, I'm pretty sure he didn't have a beak. Is he doing okay?"
I think this paragraph is really exaggerated.
Why, you ask? For one thing, making Santa Claus an animal rather than an old white male could spare millions of nonwhite kids the insecurity and shame that I remember from childhood. Whether you celebrate the holiday or not, Santa is one of the first iconic figures foisted upon you: He exists as an incredibly powerful image in the imaginations of children across the country (and beyond, of course). That this genial, jolly man can only be seen as white—and consequently, that a Santa of any other hue is merely a “joke” or a chance to trudge out racist stereotypes—helps perpetuate the whole “white-as-default” notion endemic to American culture (and, of course, not just American culture).
If kids feel such shame and insecurity as a result of not being white like Santa, then why won't they feel shame by not being a penguin like Santa? I can't help but imagine that it's a small minority of non-white kids who feel persecuted because one of their heroes isn't the same color as them. I never gave a shit that Michael Jordan was black, and that I could never be like him. Most kids don't think like that. Changing a tradition like one of Santa Claus for this reason is a little over-reactive.
It seems like the only defensible reason Santa should be changed from his current form is so someone from any family can dress up as Santa without raising questions of Santa's race. While there may be some legitimacy to the claim, I have a few issues with it. First, I don't think most families have someone dressing up as Santa and ho-ho-hoing through the house every Christmas, I know I never did. Destroying the illusion of Santa for millions of kids for the reasons I mentioned above just to appease the kids who are privileged enough to have their own Santa seems counterproductive. Second, if a kid is old enough to ask about Santa's race and feel shame for not being the same as him, maybe they're old enough to know that he's not real in the first place. I never believed in Santa as a kid, but if a kid older than 6 still believes in him, then they're in for a rough life...