Well, Ragnarok gives you the best answer then.
They're the GM and they consider that DnD doesn't always translate well into video games.
Wormerine's answer is interresting too, as usual.
Ragnorak seems to have some serious mental problems. He has not written anything worth reading so far, and is completely wrong about several points. A very primitive and angry type of animal in any case.
I think Larian should consider the long-term consequences of turning its back on the PHB if they expect to return to the sword coast in the future. If they go straight to DOS4, maybe it doesn't matter. But, after Swen's quest to get the license, I don't think he will get tired of the setting after only one game. It would be in their best interest to have more respect for 5E.