I find the idea of a good man losing his way because of a complex PTSD reaction to be incredibly sympathetic. The psychology of his breakdown was pretty bang on in terms of getting the symptoms right, especially the way in which Bruce's personal history and lifestyle choices would have exacerbated his dysfunctional condition. The resolution, or cure, was spot on as well. Not only is it clear that Bruce isn't instantly reformed ("a better superhero than he ever was"), but it's also quite common to facilitate recovery in PTSD patients by using exposure therapy, which the "famous scene" most closely resembles. It's also just a classic revenge tragedy story in which the hero's tragic flaw is redeemed by grace. It's a shame it didn't work for you. Still, that deconstructive characterization is no longer Batman's status quo. He's in the process of pulling himself out of the hole he dug for himself, which includes mentoring again (Barry) and working with others. Reconnecting with people in a group, especially a group with shared experiences, is also a common treatment for PTSD. Superman's death was the first step in a journey.
ETA: I see Affleck's Batman or his arc as resembling Saul/Paul's in the Bible and Edmund Pevensie's in The Chronicles of Narnia: The Lion, the Witch, and the Wardrobe. They're dynamic and compelling characters whose dark pasts enrich rather than tarnish their stories.
