'Twas not always thus...at least, from an interface perspective. The 10-speed I had back in the bad old days had a Suntour (I think) FD that was reverse-action, so that both levers were set up to move in the same direction for "harder" gears.
Shimano now makes reverse-action rear derailers ("Rapid Rise"😉 that allow for the same sort of thing--I believe that these work against very stiff springs...
