I mean, even as a DnD player, I appreciate that you DO need to turn a profit as a company, and I enjoy my favourite hobby getting wider attention. I'm actually not opposed to them making this into a bigger franchise because I think that it IS suitable to fill that sort of Marvel role, contrary to the article. It has clearly defined heroes and villains, iconic designs, and very flexible storytelling, all of which CAN be compared to a more mature Marvel. Making a handful of recognisible heroes and villains and promoting them honestly seems like a perfectly sensible and legitimate business tactic.
HOWEVER.
As a DnD player, I also actively dislike the story design in most official content because it's painfully generic. Everything is made to be very comfortably within the realm of mass appeal and staying within the realms of conventional fantasy. They have unspoken rules and tropes that they simply Do Not Violate and as a result they struggle to craft stories that aren't predictable. They are noticeably complete shit at having any idea how to make a force for good that's more powerful than the players that isn't used as a punching bag to make the players feel like they're in danger. And my point is that they COULD and should take more risks when doing storywriting and character design, because the nature of DnD is that even if you totally fuck something up, because everyone runs their own worlds a retcon isn't going to destroy everything- and more than that, writing out a story, while time-consuming and requiring effort, is nowhere near the money sink that a movie is. It's fine to take risks! Defying conventions is OK! It's completely fine if not everyone likes each product, so long as it's well-made on the whole!
Otherwise the game is also super unbalanced (I know this because I have extremely extensively created homebrew for it, I can tell you EXACTLY how and where it is unbalanced), although this isn't as bad as it would be in a lot of other games because you won't really notice the balance issues if you're just playing a casual game with your friends. If one of your friends is trying to play the game optimally though, then they can rapidly make the game unplayable by taking advantage of especially unbalanced parts of the game.
And this is to say nothing of the fact that the absolute greatest strength of DnD is the fact that players can do whatever they want. So trying to make stuff that tells players they need to act a certain way is only going to diminish that strength.