Those signs are just as guilty of pushing ignorance and hate as the cultural force you're alluding to—you perceive them to be different because their ignorance overlaps with yours and they hate the things you hate.

Signs like these take a strawman version of "the other side" and define the residents of the home in opposition to that strawman. It's evidence that the person who put it up views themselves as part of the culture war, not evidence that they strive to be kind to and understanding of people who are different than them.