People migrating to slave planets

[OverlordCW]

I have migrants moving from planets of other nations to my planets with pop policy of enslavement.
That makes absolutely no sense, why would they freely move away from their homeplanet to become slaves??

[Fenrisfil]

Well theoretically it could simply be unethical ship captains. What you have there is a slave trade. Of course if that was the case then the private economy of whatever race is selling their own people into slavery would get a substantial boost and I'm guessing that isn't happening so, yeah that's an oversight/bug. Wouldn't be so bad if not for the fact that those Empires will give you slaves and then hate you for accepting them (assuming they weren't the race you meant to enslave).

[GVind]

Worst thing slaves give colony -5 penalty for "cruel" enslaving. It makes no sense to me. All population on a planet receive penalty from 1 million useless slaves being transported by migration transports to you.