Whenever I hear a parent say these words it makes me cringe. Just because the baby teeth will be falling out eventually doesn't mean they aren't important. Baby teeth (primary or deciduous teeth) serve a great many functions for your child affect their oral health in many permanent ways.
Here are just a few of the reasons that baby teeth maybe more important than you think. First, and most obviously, they help your child chew. Proper nutrition is critically important to your child's growth and development. Second, infections of primary teeth can cause permanent malformation or discolouration of the adult teeth. Third, baby teeth help guide the adult teeth into place which can decrease the chances of your child needing braces later on in life.
For these reasons, and many more, it is important that you help keep you child's teeth clean and healthy from the beginning. A little help from you now can save a lot of problems for your children later.