The Conjuring 1 & 2 and Insidious are shit, but it's not James Wan's fault. The directing was perfectly fine, it's just the stories are the same old lite-horror fare that's popular these days. No death, no blood. Jumpscares in a creepy house. Still far ahead of garbage like Paranormal Activity though.
Saw 1 was amazing and Furious 7 was very well liked, I'm sure he'll be one of the stronger parts of Aquaman. They just need a script that works.
I personally find this Whedon discussion silly. If you want to slam him for the reshoot scenes specifically that's fine, but it's clear that this mess was far and away Snyder's vision. It's not like they cut him out right before they started filming, they brought everyone back after everything was done! Even complaining about the flat, shot-reverse shot look to his scenes is a little disingenuous considering they had to rush and do everything on the cheap, while polishing up the rest of the script.
Edit: As for those particular details regarding the "face in boobs" joke etc., those are fair points. But consider that he was still a step up from what they were working with from Snyder. That man's sensibility is a black hole.