In this discussion of E-scooters, we should not lose sight of the fact that they are motor vehicles, which typically bicycles are not (only a few have power-assist designed to ease climbing steep hills). That is where the notion of letting E-scooters drive on sidewalks and otherwise treating them like bicycles breaks down.
As motor vehicles, they should be allowed to do the speed limit on the street, just like any other motor vehicle; they have no business being allowed on the sidewalk. If city hall, echoing E-scooter companies, believes 15mph is the appropriate speed for street riding, then maybe, especially in Old Town, the speed limit for all motor vehicles should be set at 15mph (except Route 1 [Patrick and Henry Streets] and the Parkway [Washington Street]) so motorists can't carp about being stuck behind E-scooters?
The only thing E-scooters seem to have in common with bicycles is their mutual contempt for following traffic laws. So, if city hall is going to continue the E-scooter pilot program, it needs to charge E-scooter companies enough to support additional police enforcement, just as the advent of the automobile a century ago put an end to having one constable for the whole town. If city hall is unwilling to hire additional police, then all the E-scooter rules are mere window dressing city hall has no intention of enforcing because it has not provided the resources to enforce the rules governing this disruptive new technology.
We would need six additional officers to devote one police FTE to policing E-scooters at all times, so why not raise the permit fee for each company to a million dollars per year to cover the cost of this additional policing? These are private businesses which should be willing to front that kind of investment. And in the face of such a financial commitment, instead of the risible, concessionary $5,000 city hall now charges, and the enforcement it enables, many of the folks complaining about E-scooters may find themselves having to hold their tongues.