I understand what the writers were trying to do, but fell into a few traps. The race relations between the two worlds, and the absurdity of judging someone by color is spot on (pun intended), but the second part about allowing illegal immigration to go unfettered is very much a dangerous leftist trope.
If a world (country) is damaged by its people and their policies, there is every reason to believe they would bring the same tendencies to any new world. This is why immigration should only be allowed for those who can bring a substantial benefit to the host country. It is perfectly valid for world A to limit world B immigration, especially illegal. After all, wouldn't it be better if world B fixed their own problems first? Not everyone in the galaxy can live on a single planet.
This also fails the prime directive. If the Federation believes that they should not interfere in a world's development, they should clearly understand this world's desire to limit an alien population.
If a world (country) is damaged by its people and their policies, there is every reason to believe they would bring the same tendencies to any new world. This is why immigration should only be allowed for those who can bring a substantial benefit to the host country. It is perfectly valid for world A to limit world B immigration, especially illegal. After all, wouldn't it be better if world B fixed their own problems first? Not everyone in the galaxy can live on a single planet.
This also fails the prime directive. If the Federation believes that they should not interfere in a world's development, they should clearly understand this world's desire to limit an alien population.