Tbf the manufacturing standards for plenty of e-scooters and -bikes can be pretty iffy sometimes, and people abuse them in ways that can increase the likelihood of issues. I concede that the vast majority of electric personal transportation devices that go up in flames usually happens during charging. A public transportation bus has to meet higher standards than a mono wheel scooter off of AliExpress.

(Imo they should be allowed on, but I can see the point in not doing so)