Because they are usually aren't free in Europe. And it doesn't feel like a new market opening, it usually is just that single shop once every year.

And additional ancedata because I don't know whether that's a US <> Europe thing: Personally, the idea of going into dept for private consumption is completely foreign to me and most people I know, so the idea of a credit card is very unappealing.

Wire transfers OTOH are simple, practically free and fast enough (<1 day inside the country, ~1 day inside of Europe).