If you as a rider are comfortable riding a bike where you're on tippy toes, then good for you. But in my experience, because I deal with things like uneven pavement, slopes, rainy conditions, curbs, and (sometimes) heavy bikes, I don't feel comfortable on a bike unless I can put both feet flat on the ground. I'm not talking about environments like dirt or the race track. I'm referring to riding on the street. That is my personal opinion. You are all entitled to your own.