They kind of do - you can have bad actors messing with scooters. Myself I used GPS spoofer once to park out of the allowed zone (just a few meters, for lulz).
There can be people messing with the system, and limiting the OSes that can access your network looks like low hanging fruit. Just like Riot (League of Legends) banned Linux users to "solve" botters. But like with botters, there are better alternatives that don't exclude legitimate users.
Most of the larger scooter companies don't do it, so it seems unlikely operating such a system requires trying to get around the first rule of network security.
I feel like we (that is anyone nerdy enough to post on HN) have been far too patient with people who are choosing to wage a war on general-purpose computing, and it's past time to push back harder.
There can be people messing with the system, and limiting the OSes that can access your network looks like low hanging fruit. Just like Riot (League of Legends) banned Linux users to "solve" botters. But like with botters, there are better alternatives that don't exclude legitimate users.