Wow. If the writer of that article thinks that type of dancing is dirty, he/she needs to get out more.
It’s clear that TKD in S. Korea is attempting to merge with K-pop (or to be K-popish) to stay relevant to the younger generation, who are generally more obsessed with synchronized dance routines than MA. Has the quality of TKD (or at least WTF TKD) fallen? It has. A lot. But that dance routine was in no way, shape or form ‘dirty’.
Oh, yeah, and those girls DID include some TKD in their dance routine...at least as much TKD technique as you’d see in a typical Olympic TKD match, if not more (at least they did a few ‘punches’).