His statements aren't inaccurate for the most part.
There are some teams that do use drilled rotors for racing (Porsche being one that comes to mind prominently) and from my understanding their rotors are actually cast with the holes in their rotors and then are chamfered when the initial surface cut is made on the cast surface. This doesn't break up the crystalline structure of the rotor as much as straight drilling through the part does, this can be evidenced by many properly designed components that are cast with voids in them and are finished up as a machine process (the point being that a solid piece is not always better than a properly engineered piece.)
That doesn't mean that Drilled rotors are the end all be all, just that there are Drilled units that can and are designed to handle those stresses. That being said, cracking is more due to rapid temperature variations (among other variables.) For example, too rapid a cooling rate for the rotors after being heated up under continuous braking could lead to fracturing.
The statement about off-gassing is pretty true; you don't see that as much as you did long ago. So the primary goal of drilled and slotted rotors isn't as apparent as it was in the past.
Honestly for our vehicle I think a stout vented rotor (straight or curved vents) is more than fine for applications. The trick is more the pad material and what quality of iron is used in the rotors.
