Sam has never bought into family the way Dean has
No, but IMO it's because Dean has grabbed onto "family" as a crutch, it's like something that is supposed to excuse overstepping boundaries and all manner of disregarding of Sam. Because of family. I don't think Dean's perception of family is entirely healthy.

I think part of that is because Dean lost his childhood in a way Sam didn't. Dean has a huge blindspot when it comes to family and Sam knows this. Sam's reaction to what you do for family isn't at all abnormal. Dean's is. But because the narrative of Supernatural is mostly from Dean's POV, we tend to side more with Dean and less with Sam.
(my 2 cents -- I have not seen 9.13 yet so.....)

I love both brothers and their dysfunction is so painful sometimes. Ugh.



I think step-mom's version of pack and family is also fucked up, but on the other side of the coin. I felt for the preacher-dad who wasn't born but bitten and he tried to make peace with his lot in life and improve his family's chances of survival but his wife only saw his weakness and pandering to humanity.
SO SAD
I'm glad Garth has found a home!!
*sniffs*
That has made me happy. I hope we never see him again so he stays that way - LOL