Punnett squares and gene dominance/recession is a very simplified explanation for a single gene. A lot of things, like eye color, are controlled by multiple genes. And that doesn't even touch epigenetics, where even a dominant gene may not be expressed, usually due to environmental factors. So it's not wrong, just simplified, and that should be explained. If someone told you "this is how it works, and there is nothing else going on" then they lied to you. But the genetics is true.