I agree with potatolicious and dmix. Also, what's the difference between "Bitbank", Paypal, Stripe, etc. What makes this idea unique?
Who pays that? The merchant. (Well, the merchant adds it to the price that everyone pays, but I digress).
Now given the option. Pay $100 with your credit card or pay $98 if paying with bitcoin, which are you going to choose.
Stripe and PayPal both are at 2.99% + $0.30, Square is at a flat 2.75%. So giving the customer the 2% discount for paying with bitcoin still yields the merchant more than had the customer paid with a credit or (signature-based) debit card transaction.
There are so many of these alternative payments systems available nowadays, but none seem to really offer any benefits (or protection or increased warranties) to me over a credit card to change my personal purchasing behavior.
It will be some time before we see bitcoin used at retail, point of sale. But it really solves problems for online purchases -- for the merchant. And maybe that's where the the sweet spot is. If you want what the merchant sells and the merchant wants bitcoin (for the reasons you state -- protection from fraudulent customer chargebacks), you won't be given the opportunity to use your credit card.