Just this week in Vantaa, Finland three 12-year-old girls piled onto one of those electric scooters you subscribe to with an app and proceeded to get run over by a car at a crossing, killing one of them
The app is supposed to have an age restriction but it's easy to bypass and you're not supposed to have more than one person riding on one, which people routinely ignore
I hate seeing kids and teens speeding around dangerously on those fucking things and then just leaving them laying around on high-traffic bike routes because they don't give a shit since they treat the scooters as completely disposable
Fucking awful bazinga-brained Silicon Valley-ass idea and business model. Actually, there are also bikes you can use with an app but curiously you don't see kids doing reckless shit with those, almost as if electric scooters were uniquely terrible 
I can try to square that circle for you. Here's my (I think pretty reasonable) take on scooters:
Right now, with city infrastructure the way it is, they're terrible. There's nowhere to ride them safely, they get left on sidewalks and bike paths, they're just extremely dangerous right now, whether you're riding one or just being around them.
But. They don't have to be like this! Get rid of cars, put racks of scooters next to train stations and bus stations, have a bit of societal education about how to ride them safely, and boom! Great solution to the last mile problem! If there are convenient places to park them people won't leave them on random sidewalks. If streets are full of scooters instead of cars, and if we get some rules of the road engrained in the public consciousness, then they won't be dangerous, either for the rider or surrounding pedestrians and cyclists.
They could be (and should be) a great innovation, but their current implementation is so, so fucking bad, and leads to serious danger and accidents.