There are alternatives for Android phones. And the way everything is designed, if you accept either of them then the other one comes for free automatically. Actually, if you accept contactless debit/credit cards, both come for free and you'd have to invest extra effort to turn one of them off.
The point of CurrentC is that it has huge advantages for the trader, and huge, huge disadvantages for the customer. Sellers may be quite happy giving you a rubbish experience if it adds money to their pocket. On the other hand, if one store offers a nice experience that is also safe and doesn't give the seller access to your bank account, and the other store doesn't, where will you go shopping?