As long time fan of scooters, but with most of my miles on motorcycles---everyday rider since 1955, and long time rider outside of US (40 years).
1. Scooters are not really part of important transportation in US. Very few serious commuters on them.
2. Dealer network can be spotty.
3. With the scooters appealing to old/aging riders. Many not so skillfully ridden. My point here--IT TAKES MORE SKILL to skillfully/safely ride scooter than reg. motorcycle----think scooter has no footpegs to stand on,(think bumps), no tank to grip, some scooters have feet forward riding position (can hurt back)
I like the step over/thru mounting, but with no tank I find scooter without leg support, pushing around with feet---easier to tip over or get away from you. I think just about every scooter rider has had one go over at one time or another!!
AND auto transmissions do not give the exact control that reg. motorcycle clutch (skillfully used) in heavy/slow traffic situations.
Just some thoughts from still daily rider at 81. Most fun/enjoyment from scooters for me=long tours, used scooter to AK, east as far as Nova Scotia, been to 49 states with scooter----getting expensive, though. This year maybe going back to camping/sleeping along side bike---Slept in bushes in Geneva, on the bank of the Seine in Paris, in the nice Rest Areas of the Toll Roads in Japan----recent years in US, awakened by Police while taking daily nap along road.