They did sometimes have an "overhead" ThinkLight, toggled by a magic Fn+PageUp combo just like some backlights.

I think putting in key backlights made the previous spill-proof tray design not viable, so it's not a pure win and I could see why they tried to hang on to the old design.

Old Thinkpads could survive repeated spilling of drinks on their keyboard, the only laptop I've seen to cope with that. There was a tray underneath the keys with a drainage hole all the way through the laptop, that way the liquid didn't reach any zappy bits.