Two things I submit for further consideration:
1) Patty Mills has been fairly terrible on defense this year. He has had trouble staying in front of his man and gets burned a lot even against backup PGs. He somewhat makes up for this by being a 100% hustle and heart player who tends to generate a decent amount of steals, but the fact that he's rated higher than Parker is pretty telling.
2) The amount of absolutely top flight PGs in the NBA right now is perhaps unparalleled in history. Curry, Wall, Cp3, Parker, Teague, Westbrook, Lowry, Lillard, Conley, Rondo... and a pretty solid 2nd tier of very skilled PGs (Walker, Bledsoe, Dragic, Rubio, Hill...). I don't think you'll find a point in NBA history with more top flight PGs who are so skilled at managing possessions while being a scoring threat.