Well they asume the scenario to get all the land lightning strikes ... and say it is too expensive to build so many towers and not worth it. Surely true, but I thought the main reason is, that it is just too difficult. The lightning will just melt anything where you want to store it and probably take not the intented path to those capacitors or batteries and just burn something else.

And maybe with effort you could build something lightning proof, but the gain is probably way too low. Still, if I would have the funds avaiable, it would be an awesome project ...