I'm one of those people who usually gives John a really hard time, but as mizzykitty continually points out to me, John isn't really that bad - he's actually pretty damn good all things considered. And seriously, I'm willing to admit that I'm a bit of a bitch to John and he doesn't deserve all the criticisms I've heaped on him over the past few months. It's true, he made mistakes, especially when it comes to Dean; however, much like Sam's mistakes in S4, they are understandable (actually, they are even MORE understandable than Sam's mistakes, because John wasn't nearly as messed up as Sam - though, in all fairness, one could partially blame John for how messed up Sam is).
Anyway! My point is, that hearseeno's Meta on John (and how he informs and created the Winchesters as we know them) is extremely spot on, in my opinion. hearseeno manages to write about John without it seeming bias (at least not to me). John's mistakes are noted, but the reasoning behind them is so well explained that it's easy to understand why it is that John didn't see them as mistakes - even for someone like me who would much rather resent John than sympathize with him.