As an adult the only part of me that touches carpet is my feet. Carpet is for walking on right? But now that I am the father of a 5 month old, I realize how much kids interact with carpet. That's where play time is. Kids roll around on carpet, crawl on it, and even face plant into it sometimes. They also drool, spit-up on, and worse to the carpet. Despite it getting dirty, carpeting is still a great floor choice for small children, it's much softer and more forgiving then hard floor options, but it needs to be cleaned to keep it looking nice for the adults who are just walking on it, and more importantly for the health of the kids playing on it.