There's never any excuse for rude behavior on the part of an FA - but there's never any reason for a pax to swear at an FA either.

W/that said - where would the line of "borrowing" from business class be for you? I'm not trying to be snarky - I'm legitimately curious. What if there were a tray of champagne as you boarded - would you take one and think it was OK? What if there were a dozen sets of Bose Headsets in that overhead? What about an amenity kit? How is the blanket different?