Growing up on a street where the neighbors landed a helicopter at their house a few times per month I can tell you it’s extremely disruptive. As a kid you think it’s fun, I’m sure my dad was annoyed when he was trying to hear the tv though.
Not often, but I don't enjoy it when it happens; they're very loud. "Less loud than a helicopter" isn't much consolation. Noise pollution will definitely need to be taken into consideration before people start taking mini-choppers in place of Uber/Lyft.
It doesn't really make sense to call it a case of NIMBY because noise pollution is a real issue. This isn't a matter of them looking ugly; we do have to be able to sleep. If it's significantly louder than a train, that might be a bit too much.