Scooters seem to reach their limits faster than motorbikes because they have larger unsprung mass in the engine plus they are not really designed for high speed cornering.
Motorcycles and scooters experience centrifical force when turning rolling around a corner. The reason motorbike lean into corners is so the force created sideways as you turn in the bend balances the gravitational force that pulls you to the ground.
The faster a motorcycle or scooter goes around a bend, the more the bike needs to lean to balance the forces.
When pushing my scooters hard, I often bottom out the rear suspension on corners due to the increased load of the gravitational force plus the centrifical force. The faster the speed or tighter the corner the mnore load on the suspensions.
As for scooter's little wheels spinning faster and the centrifical force on the wheel having some effect on handling, the potential heat buildup due to the small mass of the tyres is a more significant aspect than the forces in the wheel.
At higher speeds the inertia of the wheels and engine of a motorbike or scooter increases the forces needed to steer the bike or scooter. My motorbike got very heavy when trying to counter steer at over 130km/hr. Its easy to see how people over cook corners with higher performance bikes, the gyroscopic forces of the front wheel and an engine at 10,000 RPM make a medium sized bike feel like a Mack truck at higher speeds on corners.
I suspect gyroscopic forces have some effect on bigger scooters like the Burgmen but most people won't punt a scooter like that around bendy roads at higher speeds to find out.
The GP racers have my full respect when I watch them toss the bikes between corners at massive speeds. The forces they are controlling are massive and they make it look easy.
2001 Yamaha Zuma, DR Evo 68 cylinder, Leo Vince TT derestricted, Delorto 17.5 (#98 jet), standard aircleaner, RMS fan, Race CDI, Standard oiler and premix @ 75:1 Shell SX2, Doppler SR3 variator, RMS clutch, RMS R rear shock absorber and Pirelli SL26 tyres.