Clearly 747Focal is not aware of the developments in electrical motors
There are some pretty heavy duty machines going about, shifting hundreds of tonnes of intact buildings and even scrapped aircraft, all using a flatbed type vehicle with electric motors. Heck I think even such a vehicle is being used to shift parts of the A380 about.
Thus I think we can dispell the thought that an electric motor cannot shift a 777 or even a 747. With the correct gearing, even I could shift one.
I have no idea how much all this would weigh though, so I can't argue with you on that.
I think the potential benefits to the environment and the fuel bill will make this a top notch idea if Boeing can make it work, efficiently and with managable weight. I think we shouldn't de bunk it so easily.