As the soon-to-be President of the United States, Donald Trump needs to be prepared to handle the incredible stresses of the job with poise, authority, and professionalism. Politics aside, America is counting on Donald Trump to be an effective leader on the world stage. Demanding apologies and lashing out at everyone who challenges him and his friends are the exact opposite of good leadership and somebody needs to teach this to the president-elect.
In short, somebody--anybody--needs to ensure that President-elect Trump is prepared to handle himself like an adult when he inevitably comes across this very kind of "rudeness" on a day-to-day basis.