Apart from that: it depends if the snapped belt just flies away or if it obstructs/blocks the rear sprocket (very dangerous instant blockage of the read wheel). A chain is probably more prone to that than a belt.
On a m/c it is, particularly when leaning in a turn. An experienced rider should recover, but it won't be fun. Also, other traffic participants don't expect a m/c to suddenly stop in the middle of the road for no apparent reason.
Never had such a drastic mechanical failure, just ran out of gas (on the GG bridge of all places) and had a blown main fuse (fortunately on the down-hill section and was able to coast through multiple lanes of traffic to a stop at the side of the road).
As far as the rider is concerned, this seems similar to Honda's DCT bikes: automatic dual-clutch transmission, which can be either fully-auto or (mostly) rider-controlled.
I'd argue that it's better for muscle-memory to have a different setup. My regular bike is of the DCT persuasion, so having different controls allows me switch my mind when I ride a regular bike. I once rode a rental with a quickshifter [0], and after longer stretches I'd forget to grab the clutch when stopping or starting.
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[0] A quickshifter isn't an automatic gearbox, but an augmentation of a manual one. Since motorbikes gears are unsynchronized, you can do clutchless gear changes by accelerating or cutting the gas briefly and simply pushing or pressing on the gear control.
Same reason I still like the idea of hybrid cars. In the cities, where people live and breath, you remove most of the pollution/wear on the engine, and on the highway you get more range and keep the engine at its sweet spot
For the extra 134 pounds over the original Ninja 400 you get a whopping 7.5 miles EV range
Why not just get a full electric like the Zero?