Is the best-case scenario that, since the force is being transferred to both wheels, you might not peel out as often when you start to ride? Well, THAT certainly justifies the extra weight, expense, and whatever portion of power is lost in the transfer!

Those little gears are cute, though.

Snow, ice or sand is the only terrain where this design would make sense. And in flat, soft and squishy terrain like sand or snow it makes a lot of sense actually. Just like cars.

But just like cars, very few vehicles need to be front and rear wheel drive.