Why does the media in the United States legitimize rioters and looters by describing them as "protestors" or "demonstrators"? ?

This is exactly who store owners need guns.   They can sit inside their stores and the second someone breaks in they can claim they were in fear for their lives from the person breaking in and shoot them.   You can bet there will be no looting.  

There are obviously the real protesters and then the anarchists who love chaos and have infiltrated the crowds for opportunistic reasons such as looting and rioting

Because they don’t paint with a broad brush like ignorant yahoo morons.