Don't you see the enormous negative trust of the user, partially related to this person accusing others on a regular basis? I've never heard of scam with Primedice or Stake, just like some others said. And while Stake is rather new, Primedice is a pretty old and reputable casino. It was the one I started my gambling path with, so to speak. And most of the other dice games are built and animated basically like Primedice did it back in the day.
I agree with the op about PrimeDice and Cloudbet as old websites that have gained the trust of gamblers. But there are also many other decent websites out there. I think a choice should also depend on one's personal preferences and priorities about the terms, design, animation, variety of games, etc.