I suppose the answer to "why would you waste..." must be "because you believed it to be financially advantageous" but, as you imply, those who believe that are probably misguided (at least, in the long-term).
I also suppose that the generators and distributors of electricity would probably welcome such a practice (whatever the long-term cost to consumers), since they would love to have vast amounts of 'electricity storage' capacity to enable them to even out the variations in demand during the day - so would presumably be only too happy if someone else was paying for it!
I can't really see it ever catching on in a big way.
Kind Regards, John
