IDGAF if their "primary interactions" are through social media. Words are just words. Period. People talk shit all the time to all genders and races. For some stupid child to let it affect them to the point they cry or (god forbid) commit suicide is absolutely pathetic.
Your problem, one of them, is that you're trying to apply rational logic in a vacuum rather than applying it to the complex dynamics of adolescent interactions.
Everything has a block, ignore, or delete function. Use them. My suggestion of "do something else" was more of a "it's insanely easy to get away from."
Ever hear of the mob affect? One of the reasons cyberbullying is such a problem is because it's incredibly effective at isolating and alienating an individual. Kids can mobilize their friends with incredible swiftness and effect, and before you know it, there's pressure on the target's own friends to pick sides. For instance, if the popular crowd paints a bullseye on you, your friends will have to choose between becoming targets themselves, or turning their backs to you.
There's a psychology in all of this that appears entirely lost on you. Plenty of studies have been conducted, and not a damn one them concluded the problem is overblown. Why are you such an expert?