All jokes aside, while I appreciate his ability to work within the studio system, specifically his ability to have etched at a career as a director of horror films (I love the genre, but studios have all but given up on it)...I don't consider him some masterful filmmaker or anything like that....
I think he's a reliable point and shoot guy.
Having said that...for as much as people hate on "torture porn" the SAW franchise *was* quite influential. The 80's had the slashers. The 90's ushered in the meta horrors like Scream/I Know What You Did/Urban Legend/Final Destination....torture porn had next and James Wan was a big reason for that. So, he has his place.
Has he taken L's? When it comes to this movie shyt, not really. Working director that can get projects green-lit...that's about as good as it gets.