I mean that Spanish bank don't control it. With Bizum they can decide what to do. By switching to Wero they would basically have to implement whatever German and French banks tell them to. Imagine Wero decides to deprecate something or update the protocol by the end of the year. Suddenly you have bunch of work to do because EPI said so.
And I agree, they have to develop a common solution and having a single European standard would be great but the fact is that Bizum, Blik, Bancoman and many more were here before Wero they are not going to switch now just because France and Germany say so. We have to push for integration and for Wero to be one part of the system.