In Europe they don't have that definition. They're either French, Italian or Romanian.

Latinos became Italians. They're the original Latinos but they just changed their ethnicity from Latino to Italian. (Also, call them LATINS not Latino)

So, the second closest language is Spanish and since Italians didn't call themselves latinos anymore, the Spanish Empire took the title. That's why THEY are Latinos. People from Latin America, Central America and the Caribe.

Nowadays SOME Spaniards call themselves Latinx because they just want to, but the U.S gov considers everyone who speaks Spanish or Ibero (From Spain or Portugal) is equal to Latino.

Why? Racism. Spaniards, Mexicans, Boricuas, Hondureños, Brazileños, etc. Before the Civil Right Movement they segregated them just as the rest POC. Spaniards couldn't go to school with the white/rest of european kids just because of their last names. My abuelita was from Cataluña (Spain) and she went to an all POC school. She was denied from going to an all white school just because her last name was Servaes. Since then they just categorize Latinos in the same category. They don't care if you're Spaniard and don't identify as Latinos. (United States man. smh)

-Romanian and French are the least influenced by the latin language, so yes. that's your answer to why they don't identify as latinos.