Here's why:
* "Brazilians" is a noun describing people from Brazil. It's like saying "Americans" or "Canadians." These are general terms and not capitalized unless they are part of a specific name.
* "Brazil" itself is a proper noun, so it's always capitalized.
Examples:
* Correct: Many Brazilians enjoy the beautiful beaches in their country.
* Correct: The Brazilians are known for their warm hospitality.
* Incorrect: Brazilians are known for their warm hospitality.
* Correct: The Brazilian Soccer Team is very popular.
Let me know if you have other questions about capitalization!