This is factually incorrect. I fly through Schiphol 10+ times a year and never had to take off my shoes. Neither did I in Paris, Berlin, Barcelona, London, Copenhagen, so "it's not a European thing" either.

I did see officers asking specific individuals to take off their shoes, with a specific justification: when either the shoes obviously contain metal, or the individuals go through the X ray machine and it complains and there is no obvious other metallic item.