I came into the game accepting that riven disposition was based on each item's POPULARITY.
SO....if half the player base adopts the Rubico Prime, it makes sense its riven disposition will go DOWN.
I will admit I am slightly sad at my less effective Amprex, Ignis Wraith, and Euphona Prime.
But I also am glad DE is taking steps to make sure the same 10 weapons don't show up on every single mission, which WF was starting to turn into.
Now if only the same could be done for Frames so I don't have to take heat every time I want to bring my fave Nyx into ESO or Arbitrations...