I wonder about this, myself. The majority of people in my own life see things like this and move on. It doesn't impact them at all.
But, the ones who do are either coming from somewhere bitter, angry, and insecure, or looking for a cheap excuse to moralize and preach. It's people who are seeking to change the world around them rather than change themselves, or people looking for that quick shot in the arm of righteous fury. Both are fulfilling an emotional need, and in typical SJW fashion, pruning things from the world that are emotionally inconvenient is par for the course.