If a scooter can go up to 25kph, I can understand why it has to be registered as a vehicle.
Lots of roads here in Vic have a speed limit of 40kph and that's for cars!
So a potential of 25kph on the footpaths or in shopping centres is too fast.
All the man has to do is get it adjusted. At about $1000, that is not cheap but it would work out cheaper, I would imagine, than having to pay rego & insurance each year.
There is another reason I think the speed should be lowered to 10kph. The safety of the disabled person.
I have a brother in law who has an electric scooter. Several times he flipped off it as he tried to round a corner and one time he smashed into a parked car and badly damaged a door, which of course he had to pay for.
He no longer uses the scooter but the thing is, he is disabled through a car accident that also caused some brain injury and a brain injury can affect a person's judgement. There are quite a lot of people around who have been disabled in similar circumstances and 25 kph is too fast for their safety.
