Because often the law cares about intent, not technicalities. Technically you could argue that this is a "whole home battery solar setups with a grid backup", but clearly the intent is as a workaround.

I'm not saying this is bad. I love a good workaround for onerous laws & fees, but random Internet commenters aren't the best at determining what workaround will or will not pass muster if a judge gets involved.

Like someone said in another recent thread: "U.S. law though is highly non-autistic and what you were trying to do is just as important as what you superficially did." https://news.ycombinator.com/item?id=49064242

Because you're asking legal question about what the law allows, not a technical question about how to exchange voltage and current.