I concur, from a strictly population-management standpoint. Hollow out the concrete jungles to make room for all the migrants.

It's a win-win, excluding the millions of people it kills. Exactly equal to abortion in every way.

As an aside: eugenics trends toward making two distinct populations, the Elite group who possess the most desirable traits for managing society's needs, and the Slave group who possess the most desirable traits for managing society's needs but in a different way.