You all hear the other day Lebron... "says if he could play with any legend it would be J Kidd because of his ability find you"
Not that Lebron's wrong, Jason Kidd is one of the best producers of quality shots for his teammates that the game has ever seen, but I do think Lebron is still not entirely aware of just how much he effects his team's offense by being the primary ball handler.
Think even Jason Kidd would have trouble finding him if Lebron played the game the way he always had in his career, he's like Rondo, completely ball dominant. When he doesn't have the ball he's not usually the type to make intelligent cuts or sneaking behind off ball screens, he's calling for the ball so he can drive on his match up.
Lebron IMO is the ultimate example of the AAU system hurting a player's growth. Ever since a young age rather than working with coaches on developing a fundamentally sound game he was playing game after game against inferior competition physically dominating his match ups and passing to teammates who are just spotting up from the same spot they always watch Lebron from. He only ever got as good as he needed to. He never really learned to play off the ball because he never had to when he was learning the game.
Which brings us to Love. Whether its conscious or not Lebron pigeon holes Love into the same role that his mental makeup believes a PF should play and Love's strengths are wasted because of it. Love's just there to kick out too on drives, swing too on the perimeter and clean up Lebron's misses. Lebron's never been able to develop real chemistry with his Love or most of his other teammates in the way that Pierce, KG, and Ray did or Duncan, Parker, and Ginobli did because he views his role on the team as the Lebron show and everyone else needs to get out of his way.
Long winded analysis aside that's just my take on why Love has fallen off as far as he has.
TLDR: Kevin Love is putting up pedestrian PF numbers because the primary ball handler Lebron plays as if he's a pedestrian PF.