People DO ride them. You see them on the streets in Japanese towns with reasonable frequency (i.e. about as often as I see heavily body-kitted hot hatchbacks in the UK).
Sure, most of the scoots over there are not so heavily modded as those in the pics, but you do see ones like in the pics, more or less, depending on what parts of town you're in (you don't see many in the CBD, for instance
, whereas it's by no means odd to see one in a trendy location like Shibuya).