I'm one of them. She kept yammering and hammering at Jack until he snapped. Now, some have suggested that it wasn't him, that someone/thing else was talking to him, acting through him. But what I saw was her in his face and him saying stop. Whether he was talking to her or some unseen force only he could hear, MARY heard Jack and still she kept on. So to me, yes, she bears some of the responsibility. A "badass hunter" like her should have known better.
I realized with this episode that the problem I have is not Dean and Sam's manipulation of Jack, that was totally justified, Duma's willingness to use Jack to populate heaven, or Jack's innocent wide-eyed 'it was an accident' attitude (but then, he is 2, so I guess that fits). The problem I have is that I just don't care about any of it. I only watch any more to see how the boys will handle whatever nonsense is going on. More recently, I only care about scenes with Dean. I know I'm supposed to care that Mary is dead, Not!Bobby is pissed and supposedly lethal, Jack is throwing a temper tantrum that could destroy everything, and Hallucifer is happily whispering in his ear. The show wants me to care about all this stuff, but I just don't. I had to keep reminding myself that Dean was grieving for his mother, because at times I was sort of puzzled about why he looked upset, or angry.
And then I was annoyed because I had to think about her, and I don't want to think about her!