There is no motive, as you can't change anything, it doesn't affect anything, and you have already made up your mind with respect to Trump. The key is not going to the dinner, why do you care the press don't question there, it is an informal gathering for a night of sarcasm and humour. People generally don't have a specific motive for posting as they are simply commenting on the story. I will admit that some people post simply to stir up controversy, however in your case I wouldn't say that. As I said in a later post it's just a dinner, not relevant to the presidency, and is more relevant to the press. What you answered earlier simply is not relevant to a dinner, relevant to a presidency, yes. At the very least you have conflated a dinner engagement with a global meeting.