That is untrue. We put a ton of work into V6 to support VMWare Fusion because they supported OpenGL 3.2. Parallels 14 was released only a couple days ago and if it really supports OpenGL 3.2 then we’ll investigate what it takes to run at this level.
Some McNeel developers use Parallels on a daily basis. Rhino may not run great on that platform, but it should run. We have just seen enough problems with it that we can’t support it very well.