It's hard to pick just one reason, but off the top of my head:
* Any failure tends to turn flying things into unguided missiles
* Noise is extremely hard to control -- I did an FAA helicopter discovery lesson, and oof
* Cities tend to have difficult to manage wind currents and hit-or-miss visibility. I was in a skyscraper across from one hit by a helicopter trying and failing to land in 2019 -- there's reasons for city no-fly zones
* Limited landing sites makes them highly situational in the first place, unless you want your streets to be helipads, which you don't
These are all fairly intrinsic and not mitigable. I can think of more issues more in the sticks, but you get the idea.
alt Hacker News
It's hard to pick just one reason, but off the top of my head:
* Any failure tends to turn flying things into unguided missiles
* Noise is extremely hard to control -- I did an FAA helicopter discovery lesson, and oof
* Cities tend to have difficult to manage wind currents and hit-or-miss visibility. I was in a skyscraper across from one hit by a helicopter trying and failing to land in 2019 -- there's reasons for city no-fly zones
* Limited landing sites makes them highly situational in the first place, unless you want your streets to be helipads, which you don't
These are all fairly intrinsic and not mitigable. I can think of more issues more in the sticks, but you get the idea.