For the sake of completeness I'd point out users wishing to remain anonymous could run their normal use wallet behind Tor with a node to help the network on a hosted server, paid anonymously with BTC, outside their country if needed. So it's possible to evade govt. detection. I do think the passport proof can be useful in many cases, though. We always prefer more not less options.
Here is a scenario. In a small country with a brutal dictator inflation is rampant. People switch to cryptocurrencies to avoid confiscation of their wealth. As they don't know any better they use government ID's in conjunction with the system. Some day the mechanism is compromised and the government obtains all records of people using bitcoin in the country. the people are arrested and thrown into jail.
better to think more about what the consequences of actions are. would bitcoin developers compromise security in poor nations to get some added benefits in rich nations? the world is a pretty big place.