i fully agree with the parking of cars issue. But for that at least exist systems to reprimand people parking outside of the alloted spots and many cities have parking spots only designated for people actually living there.
For scooters we would need a default fine, of say 20€ per scooter that is not in the correct spot or is parked in a way to hinder other people. The fee would need to be deducted directly from the company, irrespectuve of whether they pass it on.
But that kinda brings us to the point that the whole business model is bullshit, as it can only be profitable with internalizing public goods and externalizing the costs of manageing the dipshits that are misusing them, endangering the safety of other people.