I have a 2 cycle motor on my snow blower, that I bought new in the 74, used it in just about ever winter since going though snow up to 10" deep, had to make two passes to clear. it still runs like new and I still use it even though I have a larger snow blower now. I was going to put it on my bike, but looking at the cost to do it, I decided to buy the kit and keep it as a snow blower.
They used to make 2 cycle 3 cylinder motorcycles that were **** wheels and went year after year. not to mention 2 cycle cars.
So I myself I won't put down the 2 cycle for power or longevity.
It's in how you maintain and use them, as with any other motor.
For what there being used for I think they are the best choice because of size and weight.
To Each His own.