It's not about protesting, it's about representation. They were born into what are now, Germany, Germany, Italy, USA, Germany, Polish.
Why not any of the below ?
Austria: Wolfgang Amadeus Mozart
Belgium: Georges Lemaître
Bulgaria: Saint Cyril
Croatia: Nikola Tesla
Cyprus: Zeno of Citium
Czechia: Franz Kafka
Denmark: Hans Christian Andersen
Estonia: Jaan Kross
Finland: Jean Sibelius
France: Napoleon Bonaparte
Greece: Aristotle
Hungary: Franz Liszt
Ireland: James Joyce
Latvia: Mark Rothko
Lithuania: Mikalojus Konstantinas Čiurlionis
Luxembourg: Robert Schuman
Malta: Jean de Valette
Netherlands: Rembrandt van Rijn
Portugal: Vasco da Gama
Romania: Nadia Comăneci
Slovakia: Andy Warhol
Slovenia: Slavoj Žižek
Spain: Pablo Picasso
Sweden: Alfred Nobel
Why was Callas chosen over Joyce ? why was Beethovan chosen over Mozart ?
Beethoven in particular is easy. The EU doesn't have a national anthem, or a national flag, because it insists it isn't a nation, but Europe does have an anthem and a flag and of course the EU represents Europe, so it uses those, that's Europe's flag on the money. Europe's anthem is basically the bit you know from Beethoven's Ninth Symphony.
Officially the EU prefers Karajan's arrangement, if you're a huge classical music fan you'll recognise this immediately, but for most people it's just obviously the Ninth.
Marcus Rotkowitz was Jewish, born in Dvinsk, Russian Empire (today Daugavpils in Latvia) and emigrated when he was 10 (and Latvia wasn't a country yet.) At home, he spoke Yiddish and Russian, and probably didn't know a word in Latvian (at the time, Dvinsk population was half Jewish, with the rest divided between Russians, Poles, and Latvians).
Your idea that he's the guy who should represent Latvia on a European banknote would probably quickly get you burned at the stake at Doms Square in Riga.
Why not any of the below ?
Austria: Wolfgang Amadeus Mozart Belgium: Georges Lemaître Bulgaria: Saint Cyril Croatia: Nikola Tesla Cyprus: Zeno of Citium Czechia: Franz Kafka Denmark: Hans Christian Andersen Estonia: Jaan Kross Finland: Jean Sibelius France: Napoleon Bonaparte Greece: Aristotle Hungary: Franz Liszt Ireland: James Joyce Latvia: Mark Rothko Lithuania: Mikalojus Konstantinas Čiurlionis Luxembourg: Robert Schuman Malta: Jean de Valette Netherlands: Rembrandt van Rijn Portugal: Vasco da Gama Romania: Nadia Comăneci Slovakia: Andy Warhol Slovenia: Slavoj Žižek Spain: Pablo Picasso Sweden: Alfred Nobel
Why was Callas chosen over Joyce ? why was Beethovan chosen over Mozart ?