that's a great stat, where did you get it from?
I made it up. Just a personal observation. And as BrianFromWA pointed out the 1.0 number is a bit arbirtary. What I should have said is guys who are primarily volume scorers tend to have a PER/PPG significantly less than 1.0.
Michael Jordan had a career PER/PPG of 0.99. Early in his career, Jordan had a PER/PPG significantly less than 1.0. Coincidentally, the first time he had a PER/PPG > 1.0 was 1990-91 - the first year the Bulls won an NBA title.
Obviously, Jordan was a VERY complete player. A great scorer, but also great and many other things. Since PER and PPG are both heavily offensively biased stats, a player could be a GREAT defender (as Jordan was) , still have a PER/PPG less than 1.0 and be consider a great all-around player.
For a player to average more than 20 PPG and still have a PER/PPG greater than 1.0 indicates he is an efficient scorer and/or makes significant contributions in other areas (rebounds, assists, steals, etc.). Guys like Lebron James (PER./PPG = 1.18), Chris Paul (PER/PPG = 1.51), Dwight Howard (PER/PPG = 1.30), Brandon Roy (PER/PPG = 1.08) and Tim Duncan (PER/PPG = 1.19) fit this description. Guys like Kevin Durant (PER/PPG = 0.80), Danny Granger (PER/PPG = 0.86), Carmelo Anthony (PER/PPG = 0.86) and Ben Gordon (PER/PPG = 0.83) don't.
That's not to say the latter group aren't very good players. They are all great scoers, and most teams would be happy to have them. They just aren't as good at other aspects of the game, beyond scoring, as the guys in the first group.
BNM