Yes Juraj, Chaosgroup noticed how many old arch-viz designers (me, you etc...) have moved in Corona. Maybe not 100% of our jobs are made with Corona, but 80%-90%. And yes, I think arch-viz community is getting bigger every year = more money. So, Chaosgroup are running for recover this "leakage".
But, Corona is created on solid foundations to work in progressive way and run very fast, with extreme simplicity, accompanied by an incredible quality. V-Ray, as we know, no.
I remember when I started (1999-2000)with Final Render... it was so complex! And VRay was so easy, just a few parameters (compared to FR). But, now, they are exaggerating with settings, min, max, AA, mathematical calculations to set subdivs correctly, check render elements to see where are the problems, etc... in fact new scripts were born to simplify it (SolidRocks). And, now, V-Ray needs a Quick toolbar to simplify the rendering setup... Mmmm... this is why I started to use Corona. I want to spend my time to create image, not to spend so many time to tweak the renderer engine.