I think we have a fundamental disagreement. They were concerned about the DM when making 2014. In fact, they were so concerned, they streamlined all the rules. They made it easier for DMs. No more insane stacking of bonuses. No more remembering rules upon rules, and then dozens of exceptions. Nope, straight and simple (for a game like D&D). That is taking the DM into consideration. In fact, it is putting them at the forefront.
The other thing people often miss is the constant reiteration throughout the books to consult your DM. How the DM is the arbitrator. How they are the final decision maker. How they create and tailor the rules for their tables. I don't think this is a full-proof argument, because many tables design and play via osmosis. But this argument still holds some validity.
Again, those books aren't doing errata. They present alternatives to playstyles by introducing optional rules and monster abilities. I appreciate your concern and thoughtfulness, but I feel you perception and my perception are too far apart to actually come to an understanding.