Why would citizens in the newly independent country of Latvia remove this statue of former Soviet leader Vladimir Lenin?

They could do it because they didn't support communism. The Soviet Union incorporated many European states, not just Russia. If they weren't with the party they would probably get removed. Such countries were numerous, including Latvia, Lithuania, Georgia, Ukraine, and many similar countries. Many of these countries have bad memories about that period and are against the Communists and against the soviet union which is why they would remove the statue of Lenin.