As a matter of fairness and good PR, it would be great if scooter companies could find ways to enforce this themselves rather than creating grunt work for the local police.
One way to do this is with better fraud detection. There are probably many signals, but an obvious one is to look at per-account trends and ask: did the scooters charged by this account have an unnaturally low rate of being picked up and ridden by users? Even after accounting for other variables including demand in that location at that time and charge available on that scooter? If so, that suggests something has prevented people from riding them, so probably hoarding. Then you temporarily suspend or permanently ban the account.
Of course, it's possible scooter companies know they can solve these things, but they just haven't bothered yet. While they're in growth mode, they may feel their resources should be used solving other problems and Mets prefer just to throw money at the problem by putting more scooters on the street.