Nothing in this article justifies the title. Broadly their primary complaints seem to be that Hasbro is selling anything aside from a core rule set (or really anything), and that the founders of TSR were slowly pushed out. These somehow means that art is killed.
The D&D founder weren't gods. If they wanted complete control, they could have not sold their company. Or once they were out of it, they could have filed off the serial numbers and made a new system (like Paizo did years later) having learned how to protect themselves from being pushed out.
The complaint that Hasbro sells things is asinine. Sure the digital dice on D&D Beyond are tacky, but you can just not buy them. The same goes for all the toys and trinkets that they sell on the side, like pins and minis.
I especially don't understand the complaints about the OGL because it seems like exactly what they want. That's what led to Pathfinder, a competing system that Hasbro doesn't control! (Unless they bought out Paizo when I wasn't looking.)
This article fundamentally doesn't demonstrate how capitalism had any marked impact on D&D as an art form. And there are some things they could have talked about that might have landed. For instance, the need to be pushing out new content all the time resulting in lower quality or the inability to fundamentally fix real problems. They could have brought up how 4.0 pulled the rug out from under people with the way more restrictive GSL. Or how in 5.0 the only option to make money off of more than just the SRD is to use a specific site and accept a 50% cut.