Because it is solar power ultimately powering it all. If you don't care about the efficiency of that step, you don't really care about all of the later steps. It is still green energy and still cheap.
The problem with BEVs is that while it is efficient in one respect, it is insanely wasteful in others. As a result, it is an unsustainable idea and functionally just greenwashing.
Useful in isolation, but that is not what is happening here. People want to maximize the efficiency of a resource that is basically infinite in nature, while being fine with it destroying the rest of the environment in the process. It doesn't take much thought to realize that deprioritizing efficiency in favor of other factors is a much better compromise.
And this is even more stark when you realize that we are not merely prioritizing efficiency; we effectively have a cult of efficiency. One that maximizes the perception of efficiency even at the cost of actual efficiency. BEVs are still insanely inefficient compared to ideas like mass transit or walkable neighborhoods. A grid that runs entirely on renewable energy needs vast amounts of energy storage, which can't be solved by batteries without massive amounts of waste. A much smarter balance of solutions will actually reduce waste and improve efficiency. However, that imply that BEVs are a niche idea and aren't really needed in the grand scheme of things.