I think you attribute incompetence too easily. I mean, yes, often GW is just bad at balance (and AoS is by far the most problematic. At least Necromunda the rules writers deliberately go "Balance? Never heard of her"). But they are also, well, obviously seeking money with a lot of changes.
I mean, come on, they literally killed horde meta for monster meta in the edition change. They aren't THAT dumb, they knew what this would do. It isn't even meta chasers, it's just literally anyone at all playing the game. And, considering just how addicted people get to GW games, how powerful the social bonds formed in gaming groups are, I really am not sure that more people stop playing rather then grumble and buy the new meta stuff.
I doubt the hand of corporate reaches down too often, but for edition changes, I am certain it does. The rest of the time they simply refuse to pay their writers enough to get good rules, which is the actual real problem, not that they are a bunch of narrative gamers. They're simply paid too little to put in all the effort required to craft, playtest, refine, playtest, etc.