Eventually customers would have to take the log of the number of plus signs after the A, so they are switching back to A-G, and during the transition customers see two labels with different scores on the same machine. Surely you agree this is confusing?

Oh, that. Yeah, it's pretty stupid alright. The label on the right is a more modern, rescaled version, though. Intuitively, yearly classification cycle seems like an overkill. Decade? That'd be closer to the mark.

Customers could quickly compare new models without consulting a database or studying physics.

There's a QR code on the new ones helping at estimation, or at least that's the intention, and most people even semi-aware of their meter readings could probably do it in their heads. There's convenience and assistance, and there's lacking the bare-bones bedrock level of knowledge about your (household's) needs. Jab on studying physics aside, it hardly demanded of people to convert electronovolts to kWhrs in their heads.

Don't think I defend it on principle or that it's perfect the way it is, I simply don't mind them and replacing appliances isn't something people do all that often either. Is the one on the left silly? Yeah, sure. Something to grind your gears on? Hardly.