When I drank, I used to get very belligerent. My BF told me it was like "someone flipped a switch" and I became someone else. I believe him, although I don't remember half the crap I said.
Some of the things he told me I have no memory of saying, nor did I mean them. For me (because I cannot speak for anyone else) it was like alcohol took my emotions and magnified them. If I was angry or upset about something that day, look out!
So no, they probably do not mean it. However, as the others said, it doesn't mean you have to take it. My bf threatened to leave me, and that was what shocked me into getting help. I am afraid of that anger and that person i become when I drink.