I kinda want to take the last couple paragraphs of the OP, repost 'em in a new thread, and discuss that. Because those paragraphs are the real meat of the post, and they're interesting stuff I'd like to discuss. But I can hardly blame anybody for not making it that far.
Anyway--I share some of the concern about D&D's future, but it has less to do with Hasbro and more with history. D&D has had two "boom and bust" cycles now, and the root cause of the bust was the same in both cases: During the boom times, the company staffed up to unsustainable levels, which drove them to desperate measures when the boom receded.
The first bust, of course, was the collapse of TSR, which was super dramatic. The second bust was much less so, because D&D was now owned by Wizards and Hasbro, so failure didn't mean bankruptcy and lawsuits and blood in the water; and the OGL ensured the game would not die even if its owner did. But it was still a bust for all that. 3E's success resulted in a D&D team too big to justify its cost; Hasbro told Wizards that they needed to come up with a plan to reach $100 million/year, the "core brand" threshold, if they wanted to keep that staff; and thus was born 4E, with its aim to become a digital behemoth. We all know how that turned out.
So now, 5E. The 5E team made a point of planning for sustainability, limiting their release schedule and putting out more adventure paths (which players have to keep buying) than splatbooks (which they don't). All very smart stuff and it seems to have paid off. But now 5E is booming, the release schedule is ticking upward, Wizards is hiring, and Hasbro is putting money in. There does seem to be potential for another bust here.
But... is that even a bad thing? When I started writing this post, I thought the answer was a clear "yes," but now I'm not sure any more. The 2E bust resulted in an ocean of product as TSR desperately tried to juice sales. Most of it was drek, but there were quite a few gems as well (settings in particular), which people still love today. The 4E bust involved a complete reimagining and redesign of the game, and a lot of 4E's innovations were retained in 5E. Maybe even the busts benefit the game over the long term.