I have a different reading of it. I think Whedon must have accepted the JL gig knowing full well that, even if it rocked, it would still be seen as someone else's movie, just one he helped fix. I doubt he went into it expecting it would bring him anything that AOU hadn't. My guess is, WB semi-begged him to do JL bc they knew his name would bring audience confidence, and he said yes to earn clout with the studio long-term, make it his new home after Marvel. It was just supposed to be a quick gig before Batgirl, and he thought he'd either ace it relatively easily or that it would be seen as someone else's failure.
I've been reading Whedon's interviews for many years now, always thought of him as the most joyful you can be while being creative, someone who did big and lasting things with small budgets and understood his craft the way few people do. A "friend" Hollywood guy, the kind of showrunner that gets invited to his cast's weddings. It's been such a disappointment to read about the trail of damage he's been leaving over the course of his career. I think Ray's been riding this Whedon wave somewhat opportunistically, using it to air flimsy grievances over not having gotten the studio experience he wanted. But if Whedon really was this much of an ahole to Gadot and possibly others, Ray deserves all the credit for outing him when it's likely that no one else would have. I feel sorry for Whedon's kids, whom he'd mention on interviews often. What a mess of a situation, to see your dad fall from grace this irrevocably.