Bitcoin being used by everyone is the ideal situation but you need to consider that most of the population around the world are in the below-average spot. Also, you need to know that most countries are still on the 'developing' stage, which result to a discrepancy regarding their respective economic situation. Those who are poor and are in poverty have no means of acquiring stable internet connection, which is a mandatory requirement for virtual payment using bitcoin. This is the only hindrance that I see that must be addressed if you really want to push for world-wide scale payment of bitcoin.