The old UI didn't really need any redesign, or rework. Why not adding an option for people to use the old UI if so they want?
A lot of people will prefer the old one over the new one for the reasons that are currently being exposed in this forum. I can foresee a lot of complaints from players with this new UI.
This alternative would make everyone happy. Those who prefer the new, reworked interface, and those who'd rather stick to the old one.
Yeah, if they're dead set on this because of the time they invested in it, an option to revert it would be nice.