>> Why do these two scenarios evoke such different responses from people if children are being killed by a doctor in both cases?
Because killing an unborn child, fetus, is legal in the general case of abortion - that’s why. The legality provides false moral justification while suppressing outrage and scorn that might otherwise influence the decision to abort, not factoring law enforcement.
Regrettably, people do not agree on the value of life in the womb, and the law has been shaped to reflect this to the detriment of the human newbie. Yes, it’s legal to kill human newbies - that is, a fetus, an unborn child.
All humans should be afforded the protection of the law, especially when it’s inconvenient.