That's an odd take, the atomic bombings were fire bombings intended to destroy cities, unless you think the US didn't realize that would happen? The US was quite capable of destroying individual facilities. Is it legitimate to destroy a facility and everyone who works there? And their homes? And their families, and their kid's schools and everyone who goes to those schools and their doctors, and the guy who sells them snacks on the way home and his family and all his in laws and their houses and their doctors.
Seems a bit excessive.