The masses run hot and cold. Bitcoins will act just like gold. Up for years then down for years. It was below $200 in the mid 70s now it is above $1450 but was several hundred dollars higher at the start of the year.  You have already seen one spike in Bitcoins just a few weeks ago. If it had stayed at that level for a few months and then dropped by 50% a lot of people that think it is so cool would be saying it is junk. The one thing I remember from public school is the Tulip Bulb Bubble. Everybody thought it was cool until the day it was not.
I am not putting Bitcoin down I am just saying when something is hot it goes up in price, when it not it drops in price. Merchants may have a problem if the price is volatile or rises too fast. The time delay between buying and selling could take all their profit just like the dollar in the currency market.  Only time will tell with Bitcoins. In some ways they are just like Apple stock it was the richest company in the world until the big boys took their profits. Who knows the Federal Government may come close to a balanced budget in a few years.
I agree that people should live within their means. Some debt can be good like buying a house to live in but not to flip. Or a car loan for 2 or 3 years but most credit card debt is bad if you are just buying stuff. If you are just buying stuff than you need to pay in cash or use your credit card like cash and pay it off at the end of the month.