On my commute there is a ferry. I don't know what it's called in English, but I have this monthly-travel-as-much-as-you-like-card that I need to have handy. To access it I must first take off my gloves and then my backpack. Rear pockets are just not accessible when you carry something on your back.
Life would have been so much easier if they could put a front pocket on cycling clothes. I started commuting only five months ago and when I bought jerseys and jackets I went for the three rear pockets solution. I had the impression that if a jersey don't have rear pockets it's not a cycling jersey. But would the same thing apply if they added a front pocket? What's the big deal?
Don't tell me to change to panniers. It won't happen. It's not the backpack that is the problem.