Except that to my knowledge (correct me if I'm wrong) they still have non-closed loop emissions--no catalytic converter or EGR--which would mean a brand new Rotax 912 would emit more NOx, CO, and VOCs than my 20 year old Mazda gas engine car. I feel like it is my right to "rag" on something which doesn't have to follow the same rules as I do.

To be fair, my neighbors probably emit 10X the pollution running their backpack-mounted, gas-powered leaf blowers and open fire pits year round. I rag on them too, and display my rake in protest.