Bitcoin's use will never be for that. The current system used for day to day shopping works perfectly. The banks and the payment processors that are established are all giving efficiency and convenience to their users so Bitcoin has no place in it. Where Bitcoin thrives and will thrive more is in the black market and online dark markets simply because the banks do not serve that space.
So basically you think that bitcoin is only good if you are a gambler, tax evader or black market user?
I do not consider it only good. It is a really excellent tool for doing illegal stuff online. Have you seen the interest from ransomware using hackers? It is increasing. I will not be astonished if we find out that different terrorist groups are using Bitcoin as a tool for value transfer.
Blaming BTC for ransomware is like blaming RSA encryption schemes or any other encryption method - because thanks to them our files can be targeted...
Cryptocurrency is a just a catalyst for every cyber crime but it is too late to back off, if not BTC they would be using LTC, ETH, XMR or Dash - it doesn't matter.
That is not the point. My point is there is an increase in some illegal avenues of Bitcoin's use case. Whether or not Bitcoin caused it or not is irrelevant in what I am trying to say. Like you said, it is a natural evolution in cyber crime. Well the use of Bitcoin is already part of that evolution and it will not stop there, it will grow over time and at some point it might be impossible to stop it. It will become a part of society's ills in their life with the internet.
I would say that is an excellent use case for Bitcoin if it becomes widespread and unstoppable.