I mean - I get the idea but...
A) DPS only matters for a few untis.
B) DPS can go form hero to zero depending on the matchup.
C) You'd almost never pick a unit just for their DPS - the traits are far more important and since their are very rare duplicates you dont really get a choice.
~~D) ~~
I could go on - but you get the idea... DPS is important, but it does not really affect my builds.
If I have to decide between Rengar and Ahri I do so because of what I think I need in my comp right now.
The stats and roles of each Champion are so different that I'd consider a DPS-meter is the games current state as vasted resources.
Resources that are desperately needed at bug fixing, visible Champion stats, scalings, item combinations, trait lists, pathing and target updates and last but not least champion balancing (AKA NERF DRAVEN!!!)