Why can't I have a normal baby?!

Years ago I was at a meeting, stake conference, I think, and I was standing in the back of the room with my fussy baby Tyler. There was a baby girl laying on the floor on a blanket not too far away. To my utter astonishment, she arched her back so that only the back of her head and her feet were touching the floor, and scooted over to me. I thought it was the craziest thing ever! I figured she was the only baby in the world that had figured out how to get around that way.
Wrong. Another baby, this time closer to home is headed that direction. It might be hard to see in the picture, but her back and bum aren't touching the floor at all. We have a nurse that comes once a month to make sure Allie is developing properly, and when she saw that, she told me we need to stop her from doing it because if she figures out she can get around that way she won't crawl, and it will wear the hair off her head, and she could even get calluses. Weird!
Now I'm afraid to put her on the floor. She spends a lot of time on her tummy (mad), or in her exersaucer. She doesn't want to roll over, she wants to walk instead of crawl, and now this. Such a funny girl!