There are also culture and history factors in the acceptance of one medium as a currency. Platinum never replaced gold as a medium of exchange, although it has more superier properties than gold
Neither one of us is arguing that gold was chosen because of its qualities. Consensus, remember? Same goes for Bitcoin & CopyCoin. Except neither Bitcoin nor CopyCoin have "culture & history" to fall back on, but ... irrelevant.
Check this:
The information is now double every 2-3 years to expand human's whole knowledge base, so does the speed of generating a history. It took bitcoin 4 years to reach today's status, that is almost equal to gold's thousand years, information wise
There are also culture reasons behind bitcoin's rise, mostly due to a sentiment change after financial crisis and bank bail out. People now have more knowledge about banking and money, and they start to seek for other alternatives after they understanded what banking really means. They need a trustworthy saving medium that can not be inflated by central banks. Although gold suits the purpose, but this is a networked society, an electronic form of value storage is better
And, new IT generations with totally different mindset and computer skills, they generally welcome a special type of payment method that is fashion and cool. I found out that it's much easier to teach my little sister to use bitcoin instead of my father
So, the consensus is: The supply is fixed and demand is rising forever, means value will rise forever
This consensus is not unbreakable, the only variable is the demand. If one day, everyone could get as much loan as they want without worrying about returning those loans in the future, then the demand for bitcoin as a medium of saving will be very limited. You really won't care weather VISA will charge you 3% fee, as long as you could get a 10% bigger loan from their credit card every year and never need to payback interest
But I don't think that is likely to happen. In fact, many people has already borrowed quite much for their house and they will stuck in the pay back process for nearly a decade, combined with more automation and less job, their future outlook is getting worse
Another thing, with less and less investment return and longer and longer life expectancy, those almost-broke-pension funds are desperately searching for investment opportunities, bitcoin will become one of their target