I don't agree with your reasoning here.

By any measure, de-centralised currencies are a step away from "government control". Yes, government can issue a "cryptocurrency" but they can't control it other than by "hoping" then people will use theirs instead of another crypto.

Lets say they "declared" it legal tender and allowed people to pay their taxes in "govoCoin". So what ? It's not a substitute for true control such as the central banks now have over fiat. The mechanisms that governments use to control fiat are numerous:

[1] - they are sole issuers

[2] - accept taxes

[3] - (And this is the biggy). The ENTIRE worldwide counterparty network known as the banking system works as a government proxy by controlling every electronic transaction down to the last penny with known members of the public

You're falling into the same trap as many anti NWO-ers who can't see past the word "electronic" currency. It's not the fact that they are "electronic" that's the problem. It's the fact that they are centralised and corruptible. We live in an electronic age. Currency and store of value is going to be "electronic" whatever it's nature. As I said above, gold was the "Bitcoin" of the old physical market. But it has a slight problem with travelling through wires. We now have a worldwide electronic trading platform who's tentacles reach almost into every household. It's up to people to take control of it and not allow it to be cenetralised under a few corrupt authorities. Cryptocurrencies (if you truly understand the technology - as opposed to just taking panic attacks because the NSA 'invented it') are one way to do that.