I can't see anywhere where LCD has been impolite or discourteous. She is merely stating her frustrations with passengers who feel the need to question her instructions as a crew member. No-one here has any idea in how she deals with this in the cabin - only LCD.
Personally, I object to passengers who come on to this forum and lord it over airline staff on here - staff who are trying to help, on their own time - and expect staff to revere them because they are customer and 'pay our wages'. Passengers deserve to be treated with respect as fellow human beings, just as crew should be treated with respect by passengers.
However, at a point where a passenger feels they are entitled to by-pass regulations, all aviation authorities empower their cabin crew to assert themselves to resolve an issue by whatever means. For example, I had to deal with a complaint at BA where a passenger stood up just after take off, opened a locker and stood there while rumaging through her baggage looking for her ipod. A crew member, still strapped in to her jump seat yelled at this passenger to sit down - as trained. This customer wrote in to say she was embarrased, that the crew member was rude, etc but what is this crew member to do? Get out of her own seat and quietly ask the lady to sit down? Why should the crew member risk her own safety?
I also think we need to remind people that this is not airlinequality.com. This is a pilots' forum and they have very generously given space for passengers to ask questions. I don't believe the space was allocated for frustrated passengers to have a shot at cabin crew and ground staff at every opportunity, or remind staff of who pays their wages. Staff who contribute on here have to put up with this reality in the terminals and on the aircraft everyday. They shouldn't have to put up with it here. This is a place where staff should be able to be themselves.