The funny thing is that, if I remember correctly, he really wrote him as rather more sympathetic than Bruce in both the scripts he wrote for Under the Hood and its movie, even if he didn't intent to. I mean; it usually happens with well written anti-villains, but in this case, it's not even hard to understand or even sympathise with him on some of his points. I know this happens even with more renowned writers--Moore's Rorschach, even if not a villain himself, is not mean to be sympathetic at all, but even so, a lot of readers do sympathize with him.
But in this case, I would think it's easier to understand how; because, well, Bruce was honestly the coldest, distant, unfeeling person ever and seemed to not even try to understand how this come to happen and how psychotic Jason could feel so betrayed and forgotten, and put such awful plans and actions to work; the reasons behind. We are supposed to see the whole story more by Bruce's eyes, but we have more emotional feedback from Jason's POV, and that way it's way easier to take a part in the conflict, or at least, be more understanding for his part. Whereas for Bruce we get, what? Him feeling guilty and responsible for Jason's behaviour and death? And I may be misremembering because I have the movie fresher, but that thing about calling him a soldier is all sorts of messed up and one of the reasons I dislike modern Batman. Robins are kids, partners and even sons/brothers, or supposed to be. You really have to remember the kid who turned mad as a soldier? Really? Agh! I hate modern Batman. I think I would take TAS Batman, 80's Batman or even Tim Burton's Batman any day before what we ended with; who appears to be someone absurdly manipulative who seems to only feel and show ocasional rage or depression and seems to care for others in a very twisted and cold way, if he does care at all--like with Selina now, with Damian before and so on. One at a time!
/rant