The leader of the United States encouraging law enforcement and the military to shoot American citizens for looting, that's the line.
That's an extremely literal interpretation of his words. Most people would interpret that phrase to mean "you better think twice before looting because I'm not going to sit idly by and let you do it" but in the form of a vaguely threatening, yet catchy rhyme.
Even if you're right, which you're not, what is "Most" here? 51%? 63%? 90%?
Are you saying that it's bad if the majority of people are riled up to engage in violence following his tweet, but OK if 40% do? 10%? 1%?
Previous US presidents were careful with their words, as they know people will interpret them in different ways if they aren't crystal clear. Trump just does stream-of-through -> keyboard -> twitter, and we get to see the results. Which tends to leave lots of what he says open to interpretation based on the perspective of the reader.