Central Europe of course has "diatonic" accordions. That is no reason to dismiss their cultural values, even if their jigs and galliards were demonic. Or were not. It's not for me to opine.
Satan engenders hate wherever he goes and what could be more hateful than this? Yeah, yeah, I know, they think they're in love but what happens when they die? Satan has plans. Big plans. Do you want those plans to become real? I don't. That is what prayer means.