It's probably been said countless times before, but BitCoin isn't as flexible as cash is.  It's true that BitCoin is instant and you control your own funds in your own wallet, but the ease of use is still a little way off compared to even tap and go style cards out there.

On the other hand, BitCoin is great for sending cash to others in a much more secure way than WU / PP or the other brands out there - you're sending direct to the recipient and they don't have to wait for the funds to clear.