Pls, explain plainly the meaning of "If only...." in the following sentence. Thanks in advance!?

As a driver, I try to be as generous. If only today's pedestrians were not so distracted by their iPods and mobiles that you can't tell whether they want to cross or not. Stopping to let someone across is a mutual thing: the beneficiary is supposed to signal a gentle thank-you, too. So far, I would say, we're just about holding the line.