Our actions have consequences. I like to ask people what they think about people blocking highways to protest against Donald Trump. People doing dumb things like blocking highways in protest of Trump or pulling his leg in a really makes it easy for his campaign to lump everyone who says he is not fit for office into one group.
Similarly, people who are sensitive about stupid stuff makes it easy for people to lump everyone who has a grievance together into "them" and dismiss their grievances at once. Think the boy who cried wolf but rather than just that one boy getting mauled, it is every single shepherd boy who gets mauled.