I think they could have stayed with the 800cc and just increase the minimum weight limit.
Maybe there are not accidents caused at high speeds, but I think you all remember few accidents that happened on the crest at Mugello when few drivers had huge accidents there. You can always say that reducing the speed by 20kph would not make huge difference, but honestly the signal given by the authorities is the not right one (increasing the speed of the bikes).
I personally find silly doing 330-340-350kph on a bike. In F1 they tent to try to limit the top speed to 300kph and yes the cornering speed is higher, but what if you have brakes problems at the end of the straight on a bike at 340kph ? I would say that 300kph would be a good max top speed for bikes.
Just my opinion but its scary to see how fast they are going these days