Once you have "so many customers" it makes it easier for the rest of the world to join the revolution. Buying an asset with similar characteristics as gold but safely stored anywhere you can write a number (even your brain) and being able to transact with extremely low fees (making micro-transactions possible) without third parties in matter of milliseconds.
Crytocurrencies and blockchain technologies will change the world as we know it right now, enabling a new Internet layer to transact value and not only information. The single big question that arises is if current implementations are the "MySpace or Facebook" of blockchain. Will they succeed or do we need a second generation of tech? Only time can answer that question. My gut feeling is that the better open source implementation will evolve and take the lead.
Your premise to dismiss cryptocurrencies is that you don't believe I'm gonna be able to keep using these three functions in the future. We had cryptocurrencies close to 10 years and the next 10 years just look brighter than the last.