Lambie is actually on the ball here. Bitcoin's best use case is illicit transactions. It's a tool to reduce the power states have over their subjects. The overhead involved only makes sense if you can't rely on a central power to keep people in line.
IOW, if you're fine with how the political process works in your jurisdiction, and see no need to curtail the economic powers of the state, I don't see what good Bitcoin is to you apart from speculating on the price. I doubt it's actually more efficient than VISA all things considered, for example.
(Disclaimer: not read Yrpaper's contributions, so apologies if this has been covered)
I agree up to a point - evading capital controls, sure (step forward, China). When it comes to Lambie and illegal transactions, the wee soul has an obsession with drugs and kiddie porn. At least with drugs, cash is king in my city - people wouldn't risk drugs being posted to them and tend to scorn Silk Road and similar. And they'd point out you can't roll up 20 BTC to hoover a mirror, waiting for a BTC transaction is frustrating in a crowded, dark nightclub, etc.
Maybe kiddie porn is different, I dunno. The folk who get caught seem to get caught through their use of the Internet, so maybe. The British paedophile Jimmy Saville apparently never owned a computer because he thought people might see through his mask, but he's possibly the exception.