Earlier quoted context omitted.
Cars address a different set of requirements. You use one when you need to transport many people, heavy cargo, tools, etc. A scooter does not solve any of those problems. A scooter does allow a single person and their possessions to travel at faster than walking pace without getting sweaty. In the CBD that is not necessary, since public transport works so well. In the suburbs a scooter is more effective.
Sure, but look at your typical freeway rush hour traffic jam— how many of those vehicles really have multiple people or heavy cargo? The point is that for short commutes and as a last mile solution to extend the coverage of public transit, scooters are amazing. And a rental system means they can stay downtown instead of needing to take up space both ways on the mass transit vehicle.
I'm not sure how that's relevant. You edited my comment to try and make it apply to cars, but it does not - cars are necessary both in the CBD and out for instances where you need to transport cargo etc, while scooters are less necessary in the CBD if you can use good public transport instead.
The fact that many people use cars when they aren't necessary is not relevant, other than to note that there's a lot of potential to reduce traffic by replacing single-occupant cars with personal transport.
And I'm not claiming that scooters or scooter rentals are bad - I love my scooter and see scooter rental companies as a big part of reducing the number of cars on the road. But why do they insist on deploying in areas where scooters are not wanted? Why not focus on the areas where they are most practical?