Well, because of all sorts of things, not least of which has been described in this post, which had me laughing out loud.
Course, I don’t have any kids, otherwise I might’ve not laughed quite so hard. Still, as my nephew (5 years old) confided to me that he spoke to Santa on the telephone, I’m not sure that it would make a whole lot of difference to him; children know that they understand the world better than grown-ups, and they are of course right.
Maybe the problem is that more and more people have only one kid, which means that they believe that they can keep the silly-Santa thing going longer than it actually ought to. (By the silly-Santa thing, I’m talking about the idea that Santa actually exists on the same plane of reality as everybody else, which, as any child knows, is palpable nonsense.) If Google Earth doesn’t do the trick, somebody’s big brother or neighbour or cousin or friend-at-school will do it. The thing is, if a child’s belief in Santa is destroyed by his or her learning that Santa doesn’t live on our planet, then they were half-ruined to begin with. Every sensible child knows that Santa lives in the same world as their “imaginary” friends, who are not imaginary at all, but visitors from another reality, like Peter Pan, the Tooth Fairy, and Alice’s White Rabbit.
The trouble with all of this panic is that our assumptions are so small. Everybody with good sense knows that Santa doesn’t live at this North Pole; every sensible person in the world knows that the Arctic Ocean is exactly that, an ocean. Everybody (who isn’t European, who have their own misconceptions about Santa Claus, who lives alternately in Finland or Greenland) with good sense knows that there is a parallel world inhabited by Lost Boys, fairies tooth-collecting and otherwise, Puss in Boots, Santa, flying reindeer, workshop elves, leprechauns, unicorns, gryphons, and other magical beings, and that there are holes in our world that get us there and back. And everybody with good sense knows that ordinary physics and geography just haven’t got the tools to discover the ways into that world.