How does the pro-abort culture rationalize this form of gender-based violence?

One answer in the U.S. is first-world blindness to practices like this which are widespread in non-first world places. Elitism is elitism after all.

“Opposition to pro-girl legislation reveals blatant hypocrisy—pro-abortion organizations who profess they act on behalf of women and girls but support the act of sex-selection abortion whose only purpose is to end the life of a girl. Abortion is so sacrosanct to the abortion movement that it is willing to sacrifice the lives of millions of girls on the altar of ‘choice.'”

The global pro-life movement will continue to speak out and defend the girl child. We must work to oppose all acts of gender based violence, protect women’s and girls’ lives, and seek consistent non-discriminatory life-affirming laws and policies.

Source: Girls Just Want to Be Born