The chemicals that make up Teflon (the patented thing) and other "non-stick" chemicals have been shown to be really bad for humans in some cases/forms of the compounds. Especially if you're cooking your food on the surface and then consuming it every day.

Also once damaged or scraped, those pans often degrade quickly and lose the whole non-stick thing. The best way to achieve optimal levels of stick and non-stick behaviour while cooking is to know the fats and temperatures you're working with.

Also you always lose a little to the pan, when did we decide things should never stick on the pan? It's against God. (jk)