Because Jesus doesn't consider anyone to be a waste of time. In fact, if there was a type of Election in which it was eternally decreed who would be created for the purpose of comprising an alleged, eternal flock of the Father, it would be the ones who did not make the cut, that Jesus would want to save the most, and who He would save first. That’s the Jesus of the Gospels who states: “What man among you, if he has a hundred sheep and has lost one of them, does not leave the ninety-nine in the open pasture and go after the one which is lost until he finds it? When he has found it, he lays it on his shoulders, rejoicing. And when he comes home, he calls together his friends and his neighbors, saying to them, ‘Rejoice with me, for I have found my sheep which was lost!’ I tell you that in the same way, there will be more joy in heaven over one sinner who repents than over ninety-nine righteous persons who need no repentance.” (Luke 15:4-7)
Footnote: While salvation is indeed to the Jew first, and then the Gentile (Romans 1:16), that’s also from the perspective that both camps are lost sheep in need of salvation, despite Israel’s election. In contrast, with an alleged, eternal flock of the Father type Election, none in that flock could genuinely be considered lost sheep.