You're creating a straw man. That's not "prioritizing". The laws of war still hold - Minimize civilian casualties whenever possible. "Prioritize" means that if you absolutely have to choose, the wise decision is to kill the hostage takers. But often you don't have to choose - You can save the hostages while dealing with the hostage takers. In your bank scenario, there's no way those robbers are going to escape and their primary objective is money not killing, and so the police can afford to wait it out.

But in Israel & Palestine, the hostage-takers easily get away, and their primary objective is to kill.

All of the hostages Hamas took are probably dead now, and that was the likely outcome: Israel has properly prioritized killing Hamas over not doing anything to fight back and passively "negotiating". I guess if you want to be on the team that just sits back and negotiates, that's your choice. Hostage-takers will target your team over mine.