The thought of not cooking something because it would piss off the neighbors has never occurred to me. I guess that's my amarican selfishness lol
The Japanese are just very particular about strong smells and sometimes strong flavors in general. The thing about making smelly cooking though might just because of how high density the cities where most people live. Most Americans don't give a flying fuck about things with strong smells because a lot of the food we make is very strongly flavored with tons of aromatics compared to the Japanese
Also, if you eat onion or garlic, those foods have high sulfuric acid which gets mixed into the oils of your sweat and saliva which makes you smelly. Personally I love the flavor so I don't give a fuck about being smelly, and luckily most people where I live would agree with that assessment