Summing it up, the reason behind it is because FeralHeart is a reflection of real-world pop culture, albeit on a smaller scale.
In my opinion, anyway. xD
Like Faolan brought out, this happened similarly with Gangnam Style, or really any popular dance. It's a fad, and since "twerk" is now used in the mainstream English language (and likely extending beyond just English), and how strongly our younger generations are entrenched in social media, which in turn is strongly entrenched in pop culture and the wave of "twerking" that happened since Miley Cyrus' reboot, it's no surprise that users associate any booty-shaking or movement whatsoever as "twerking."
Just as well, everyone knows what twerking is, and it gets a big reaction no matter where you go.
Popular/well-known word + big reaction + "funny" factor = It gets attention very well, which the kiddos will often thrive on, using it to appeal (or at least stimulate) the pop culture side of us that everyone is familiar with (even if you don't like it xD).
Unfortunately it does get a little derp when someone uses even Headswing as a reason to yell "THEY'RE TWERKING." I saw some users in Bonfire once yelling about "Zira's twerking!" when the only Zira on the island was Headswinging. Indeed, the character's buttocks do move in that action, but it's side-to-side, rather than the front-to-back booty-popping associated with legitimate twerking (too many things sound so "off" about that sentence, I just--).
So it's not even accurate, yo. >o>
But, again, it's popular, and it tends to grab your attention because of its appeal to pop culture and the "rebellious" fact that it's a rather provocative dance that you wouldn't want grandma to see--but it's not so bad that it's worth a warning in the game.
So. Eh. *shrug* What can ya do. Chances are there'll be another fad coming on in pop culture that'll sweep across the internet and worm its way into FH's chats right along with it.
Until then.. Brace yourselves for the continuing onslaught of twerk references. There's really no effective way nor legitimate enough reason to stop or even lessen it, so it's not really worth worrying about it so long as users keep it clean.
