When your gearbox is is neutral, the clutch basket and plates are spinning together.
There are no synchronizers on bikes to slow down or match shaft speeds as on cars, so when you engage the clutch and place it in gear, the rotating mass of the steel drive plates, friction plates, and hub have to suddenly stop.
That energy is conveyed to the output shaft, and onto the wheel.
A higher idle or engine engine speed means even more energy to suddenly stop.
Since these are wet clutches (meaning the clutch plates are bathed in oil), the viscosity of the oil can cause drag on the drive and friction plates as well.
Especially since the disengagement distance is not all that much.
These bikes use a hydraulic clutch mechanism, so it should automatically maintain proper clutch adjustment.
But on bikes that use clutch cables, the cable can stretch over time, allowing decreasing disengagement clearance with progressively less clutch disengagement, and therefore clutch drag.
Don't feel too badly about the clutch. Indy cars and older F1 cars use a similar method.
I've watched an Indy car in the pits shred a gearbox due to impatience.
Rather than allow the engine to idle or run a low revs, he revved the engine way too high and snicked into 1st.
The rotating mass of the clutch and gears at those RPMS sheared the engagement dogs right off.
The same can happen to bike as well.