It's not really a half full, half empty problem, no, in as much as Crabbylioness sees Jack's "issues" and uncertainty and lack of emotional depth, generally, as a marvellous bit of subtle characterisation showing us a guy who just doesn't quite know what he feels, whereas I see pretty much the same thing as evidence of the writers' reluctance to explore exactly where the character stands and, indeed, what he feels. I think it's a bad thing, and I think it's a bad thing that's indicative of a lack of thought on the part of the writing, whereas Crabbylioness thinks it's indicative of a wonderfully thought-through masterplan. There's a difference.