The thread is called "The NBA has a 3-point foul problem," not that the problem is with Harden... It's not, it's an officiating/rules problem. Harden's one of the best at drawing these fouls, same with Chris Paul, Paul Pierce, and a dozen other guys.
The league determined 20+ years ago, that high scores were more important than entertaining basketball, or at least, that high scores were an indication of entertaining basketball, which they're not. Officials are more apt to call a BS defensive foul that sends a star to the free throw line than they are to call a blatant offensive foul that results in a turnover... because they've associated points with entertainment.
This post season, especially the first series, Harden went off with scoring, games of 34, 44, 35, and 37 points... He scored almost 200 points in 7 games. A problem for the NBA is that almost 40% of his points came from the free throw line in those 7 games. The NBA doesn't care because the stories of putting up 40+ or 35+ in a playoff game are good stories that get people to tune in... But in some of those games he took more free throws than field goals. For fans, free throws are boring... It's dead time, they usually are followed by official time outs, there's too many of them, and stars make free throws about as much as kickers make extra points in football. It's a boring play that interupts the flow of the game, but officials are coached to call defensive fouls at a high rate, and ignore offensive fouls or off-ball, non-shooting fouls. The screen and foul play that Harden does almost better than anyone is a great play by him, but on most of those screens, there's movement by the guy setting the screen, or at least, there's more movement by the guy setting the screen than there is a foul by the defender. League doesn't care because they think points = entertainment, and all points are good entertainment.