It isn't even John's not showing up that bugs me, because he could have genuinely been tied up somehow or in danger himself. It's the fact that he never called back later I cannot forgive. I keep seeing fic and meta writers trying to make excuses for him, like having him be the person who covertly got the information about the faith healer to Sam - impossible, since Sam waited until he'd found the faith healer before he even tried to tell John about Dean's condition. Or by having him hurrying to watch over his sons but not letting them know he's there, stuff like that, which I find of no comfort at all because it just makes him look like more of a jerk - comforting himself but leaving them to suffer alone. Bottom line is that no matter what he was doing at the time, he should have got in touch at the first possible opportunity, even if by then he'd already had a second message to say that Dean was okay again. There's no excuse for just ignoring the situation, and it's hardly surprising that it would add to all those other times of neglect to convince Dean that his father really didn't care about him except inasmuch as he was useful to him. :(