#ramble here

Thanks, Anon! And I’m honored you shared some of your experiences. I’m glad those experiences are in the past for you.

I guess... the thing is, I do believe Sam and Dean could both love John even if he abused one or both of them (I’m not saying that he certainly did, but for the sake of argument I’ll entertain the thought...). The presence of love, on either side, doesn’t really erase the possibility of abuse. Abusers can love the people they abuse. People can and often do love and make excuses for their abusers—he’s been through a lot; it was my fault he was angry; It was X’s fault he was angry; I’m abusive, too (because I got impatient with him that one time or that other time); he didn’t mean it; he won’t do it again; he said he was sorry; he can be so kind sometimes; if only I do X or appease him in this way or become more Y he’ll stop saying/doing these things—and it goes on and on. These sorts of rationalizations can, of course, be present both in and outside of abusive relationships. We all have opinions and take sides in every part of our lives. In everyday arguments between siblings or parents or friends, our experiences will make us lean more toward one side than another. We’re opinionated beings.

There’s a scene in “Bugs” in which we see some of those rationalizations in action. When Sam looks at Max’s father, Larry, yelling/deriding Max in front of guests, Sam turns to Dean and asks if it reminds him of someone. Dean takes John’s side. He essentially responds by telling Sam that he was asking for it: he was “out of line.” Then, later, we get this conversation, where Dean again takes John’s side after seeing Sam telling Max that it gets better:

DEAN How 'bout tellin' him to respect his old man, how's that for advice?

SAM Dean, come on. This isn't about his old man. You think I didn't respect Dad. That's what this is about. [...] I respected him. But no matter what I did, it was never good enough.

DEAN So what are you sayin'? That Dad was disappointed in you?

SAM Was? Is. Always has been.

[...]

SAM Dean, you know what most dads are when their kids score a full ride? Proud. Most dads don't toss their kids out of the house.

DEAN I remember that fight. In fact, I seem to recall a few choice phrases comin' out of your mouth.

And really... whether or not Sam said “few choice phrases,” it isn’t relevant to the points Sam brought up. It is in no way a response to Sam’s feelings that he was never good enough for his father and was a disappointment to the family. Dean, perhaps unable to even understand (much less acknowledge) how toxic and smothering Sam found his life, instead brings up Sam’s wording during the argument.