What is wrong about immigration?
Slavery is bad because not only is it exploitative, abusive and degrading, but takes away people's freedom. Immigration has it's difficulties, associated with displacement and oftentimes bad economic and social status for a while, but that could happen even if you stay put all the days of your life. WAV seems to have reaped the benefits of immigration, why shouldn't others?
WAV, it seems like you view the world as one great big zoo, nice to visit, as long as those lions, tigers, bears and Venezuelan beavers stay inside their cages.
Culture (and music), isolated and fenced, stagnates and DIEEEEEEES. Let culture (and music) evolve, if it's a good culture (and music), it will keep the things that you love about it and become even better.