Disclaimer: IDGAF haven't used cash in years

Europe is a continent with countries that have literally centuries of enimity and nationalism between them. You cannot put a French building on a banknote.

Bland and inoffensive is what keeps the Union together. Its why Strasbourg exists. Its why there are Dutch translators despite the fact every Dutch member of parliament speeches in English.

I don't know that it's about "Bland and inoffensive" so much as about recognition that differences are fine. Two football teams don't agree about which team is best - but they do agree the rules of football. Without that there is no game.

Having multiple languages is more of that "differences are fine". The use of Directives rather than Regulations for many purposes allows a country's government to incorporate local differences in how we do things. A Regulation applies everywhere, but the Directive just tells your government to make local law to meet some goal. What we want to achieve is the same in Paris and San Gimignano but how we do it will vary by local culture.

I mean, half of these proposals put specific people from specific countries on banknotes. So it's hard to argue that it would be impossible to do the same with buildings.