We used to have carpet in our bathroom. The people that sold us our place had offered for us to keep the bathroom rugs, and we thought, sure, how nice! Upon moving in we understood why....there was a dinner plate-sized bleach stain in the middle of the bathroom floor which they had covered with a rug. The former owners are very nice and we see the lady probably once a week as she is a FedEx driver in our neighborhood, so we just had to laugh.
Carpet in a bathroom can just be nasty. Boys, potty training, toothpaste, water + carpet does not equal goodness.
So we finally got some tile in there a couple weeks ago and we are loving it. They tile guy was awesome and he did a really nice job. It's so much easier to keep clean and it definitely looks nicer.