Why would you hold Milo or Coulter to a higher standard than the average rapperNot really, first the Migos are not political figures like Coulter and Milo, they are musicians. You don't hold actors, comedians, artist, entertainers to the same standards as people who make a living off of politics like Coulter and Milo.
And with rap it's selective outrage. For every "bytch Ho" lyric there is a conscience lyric that many people throw out their argument to paint a one sided picture.