Geneva doesn't require what you think it requires. It does not require that you not hit a target protected by human shields.
That is not how I read them, and I think that your opinion basically negates any treatment of individuals as
protected persons under the conventions. That's because human shields are, by definition, people used to shield military targets. And the "attacking party" is often described as the "impeded party", because they are prohibited from attacking under those circumstances. The exceptions listed are usually narrowly constrained, but it is clear that there needs to be a specific military advantage gained that fits with the concept of
Proportionality (law). Dropping a bomb on a neighborhood of civilians to kill an individual Hamas leader when no attack from that location is in progress is a very obvious example of a violation of the Human Shield law. There is no enemy military action being stopped, and there is no proportionality. Your reading of the Geneva Conventions on this subject renders them utterly meaningless. However, if you think I've misread the Geneva Convention, then point me to something that supports your interpretation.