It's not even Bitcoin...it's the fact the government will try to make having cash illegal or at least a way of investigating you for being a "suspicious type". 

After all...who needs cash these days right? The government and credit card industry will be in cahoots to ensure EVERYTHING is done via card swipes or chip reads (which may or may not keep data on spending habits and other personal information), even down to buying a pack of gum at Safeway.

Orwell is as relevant today as EVER.