You're right that semantic changes may arise out of the blue when the general public is least expecting it to. But you can bet that whoever triggered that language modification had most likely been conscious of it for a long time before they were able to utilize a platform to make it happen.

I reject the premise that words and phrases must be destined to remain stagnant just because "that's the way it's always been." There are so many examples of language changing and evolving that what's "popular" may prove to be fluid in the coming years.

And, again, when their "personal prejudice" becomes actionable, the severity escalates -- and that needs to be reflected in our language.