I love it when people explain their thinking, and especially when they do it comprehensively like this, even when I disagree with them. Kudos to you @soft-pine for publishing your data set. It must've been a ton of work, and there's a lot that can be done with it that's really interesting.
That said, one of the major problems with one person data collection with no oversight, no protocol, and no peer review is that confirmation bias is a universal human experience and is very hard to control for.
As a small example, Dean here gets good parenting credit for teaching Jack to drive and taking him fishing in 14x07 when Jack is dying (as he should! this is awesome traditional fatherly behavior!), but Sam doesn't get good parenting credit in 14x08 for being the only one to stay with Jack at his bedside as Jack actually dies.
And for a more notable example, in Moriah Sam pleads with Dean not to kill Jack, reminds him there are other choices, figures out Chuck is manipulating them and races to the rescue. Cas finds Jack, talks with him kindly, and reassures him they'll find a solution to his soullessness. Neither of them get good parenting cred for this episode. Dean does though. For this:
Don't get me wrong. It's good that at the last possible second Dean refuses Chuck's deal to resurrect Mary if Dean shoots Jack. But this is a supremely bad parenting moment. The title of the episode is literally "Dean is a tiny bit better as a parent than Abraham but not fucken much".
It must be brutal to get ratioed so hard in the notes, but man is this list of Dean's bad parenting moments strikingly short on violence and threats of violence, and especially on gun violence:
says he wants to take jack back to the bunker until they find a way to kill him
stops him from watching scooby-do and tells him he has to sleep on the couch
says he is going to stop jack if he can't be saved
figure out jack is a power vaccuum and can use that to defeat chuck
Yes, Dean has his reasons, but he threatens to kill or actually attempts to kill Jack at least once a year--and frequently more often than that--for the entire three years they are caring for him. It's not only a notable pattern, it's probably the most consistent factor in his relationship with Jack.
It's true that saying Jack's not family in 15x17 is crap parenting. But is it really the biggest problem in this episode?
Who here is being a good parent? Who is not?