Most phrases we use all the time didn't start out with any sort of bad intention behind them, because they were coined for the sake of safety and self expression not to piss people off.
But, like every other well intentioned thing in this world, some jerks just had to take phrases like "does it have gluten in it?" or "think of the children!" and ruin them for everyone else.
People once asked about gluten because they have celiac disease, and eating gluten filled foods like wheat, barley or rye can make them really sick, but then the diet fad began and made "gluten" a jerk word.
Likewise "won't somebody please think of the children?" began as a well-meaning phrase designed to get people to think about what kids are exposed to, so strippers and sailors would tone it down around the kiddos.
But now it's a PC battle cry yelled by those who seek to "protect children" by whitewashing the world, making the world a safer place by censoring the crap out of everything.
Read 5 Well-Intentioned Phrases That Have Been Ruined By A-holes here