If abortion clinics dumped their victims in the street instead of destroying the evidence, there's no doubt everyone with the least bit of empathy who didn't intentionally close their eyes would be horrified. But if the fetuses were all microscopic in size, I doubt you would see the same reaction.
The reaction in the first case is people identifying with the death of their fellow human: human in form, human in suffering, human in their death. In the latter case they are still human in their death, still have had all their potential extinguished and very much fit the definition of innocent victim.
But those latter constructs are moral abstractions in that there is nothing to look at, even through a microscope, that would trigger the emotion of empathy. I am the type of person who values my senses particularly vision in these cases. Although I understand and respect your moral abstractions, I cannot believe them without having the same religious faith that you do.