Most abortion occurs because the pregnancy is unexpected and the prospect of parenthood itself is creating a crisis for the woman. Selective abortion, which constitutes a tiny fraction of all abortions, occurs when the pregnancy is planned but the fetus is perceived as having undesirable characteristics. In other words, selective abortion involves judgments about people. Almost everyone, regardless of how pro-choice they are, has views on where a moral line should be drawn in selective abortion. Where the difference in opinion arises is in the positioning of that line.
Many feminists express misgivings over abortion based on sex.
Most medical ethicists would oppose abortion based on eye color. Important civil rights laws have been passed. However, basic attitudes towards disability really have not changed. It is a premise of the movement that a person with a disability is limited more by society's prejudices than by the practical difficulties that may be created by the disability. Unfortunately, by and large, nondisabled people don't believe it.