I think you are totally wrong here. Kids can not distinguish between fact and fiction when they are 2-7 years old. If I tell my 5 year old something, she will believe it. She has faith in me to be true and honest to her. And I love that. I will not ruin that for any of my kids.
I am not saying that kids should not pretend. They should and so should us adults, but there is a fine line between pretend and actually believing Santa come down the chimney. Right?
My kids and I shut the lights off at night and grab flash lights and go through the house pretending we are finding clues to a mystery. We also pretend we are in an airplane flying through jungles and we grab our cameras and take pictures of the cool animals. That is pretend and the kids know that. That is healthy in my opinion.
I won't judge anyone if they choose to teach their kids there is a Santa and such. I am just saying, "Pray about it. What does God want you to do?" This is hard because we want our kids to grow up like the other kids on the block. We don't like to be different. To me, we as Christians should stand out like a sore thumb and there are so many folks who won't like it. And we are told that in the Bible. Just something to think about.