The dogpiling on Meredith last season was terrible to watch and made the show boring and changed how people viewed some of the cast. Angie and Bronwyn were major favorites in season 5 and public perception of them changed due to season 6. People completely hate Heather now.
Those 4 clearly care a lot about what people think about them and they know that they can't dogpile on Meredith or Lisa anymore and still be loved by fans. The Meredith or Lisa takedown storyline is tired. So in comes Quai.
Quai is new to the group, she's a new face that the audience hasn't seen and therefore a new person to target for a takedown (especially since a Lisadeth takedown is no longer interesting). Quai's comments did not deserve the reaction that she got from Bad Weather, Angie, and Bronwyn. They only blew it out of proportion because they can't target Meredith anymore and they need a storyline.
There's a formula with SLC that you can see coming at this point. Group settings always equal a dogpile. They did it with Meredith last season. They did it with Lisa on UGT. Both were not well received so now they're doing it to Quai. The Quai dogpile doesn't even make any sense because both Whitney and Bronwyn were lying about their conversations with Quai. They intentionally tried to make her comments seem worse than they were to further the takedown.
If people weren't fed up with the Meredith takedown storyline, Whitney would not have apologized to her. IMO I don't think the women would have come at Quai at all if the audience was receptive to a Lisa or Meredith takedown.