I think some are overthinking this, honestly.
The bottom line is simple....lots of vendors thought the rainbow was on the DAZ side of the equation. What they did not count on was that when they, and 100 other vendors decide to hop on that rainbow, they bend it to the ground.
You simply can't have 100 people offering 100 pieces of slutwear, and all 100 pieces sell equally. They are simply doing what they did to Vicky4 - milking the market dry.
As for Rendo, well, they've made some really serious missteps in the last year that have cost them dearly. Between the credit card hacks (3 times, wasn't it?), the website redesign that the customers hated, and the flood of DAZ products, most of the Poser folks have simply moved on from Rendo. And, since their community manager told folks who hated the site redesign "there's the door," I doubt they will return any time soon.