dcstoevsky:

Look Dean has rational reasons for distrusting Jack and none of these have to do with Jack being Lucifer’s child. Up until this point Jack had been protected by a prince of hell and possessed his mom and Castiel in order to secure his existence. Also s12 established nephilim were dangerous because they were especially powerful, not because of which specific angel was their parent. But Dean barely gets to express the former, the latter is forgotten altogether, and Dean mostly opposes Jack because he’s Lucifer’s child. And this honestly just a poorly written and characterized means of writing a boring and passé narrative arc for Sam about feeling stained and whatever for having demon blood and having a connection to Lucifer and feeling like Dean is judges him for it.

Dean’s defended Jesse who had a literal demon parent, he defended Emma who was raised to kill him. He befriended Benny. Dean has a clear history of sympathizing with non-humans. Jack did something questionable and his existence relies on that act and so it’s perfectly rational for Dean to conclude that Jack is dangerous. It may not be right but it’s rational. But instead of arguing that he just becomes a hackily written straw man to prop up Sam’s boring self-involved narrative that’s he’s already done a dozen times already which is project his own feelings of unworthiness on people who vaguely resemble his own lived experiences.