My problem stems from the fact that we have gotten an average of 2-3 books a year and those books... really dont give you a lot. Most of it is player facing stuff and fluff text. They still have yet to give any sort for the exploration pillar support aside from traps and puzzles. Now, to be fair, its been a moment since I read the DMG, but I really dont remember it giving a lot of actually useful stuff in that area. (If im wrong, I welcome correction.)
The exceptions to this, oddly enough, are the most downplayed of the books, Ravnica, Theros, and Saltmarsh.
I know they don't do as many specific books as 3.5, but this is a turn too far in the other direction imo. Especially when they could produce smaller, specific guidebooks, like SCAG but better.
I can't help but view wotc using 3pp as an excuse to not try and innovate. Which, from a business standpoint, is fair. Though I expect more/better quality from a billion dollar company.