What are the reasons, why people use Cash or Credit Cards / ATM / Banks?
* Work offline 100%
* No fees.
* Accepted for Food Shopping & Micropayments
* 0 confermations time
* 0 exchange risks
* anyone is able to understanding of the value of payment
Well, you just don't pay cash for sex cams, do you ? O_0
On the serious note - cash is definetely better in day-to-day transactions, but bitcoin as a store of value. For daily payments I would choose something like LTC.