The second half of this article implies something that is hard to disagree with: That if modders want to earn some money from their hard work without being exploited or suffering from rent seeking, then they may need to extricate themselves from existing big business like Steam.

However the first half of the article arrives at this from a questionable perspective on paid modding and the community's resistance to it: It views modders as if they are / have been obligated to produce their work and are being exploited by the industry without compensation.

On some level, it’s mutually beneficial: modders get a “hobby,” developers and publishers get free content. But because it’s based on unpaid labor, the relationship is also highly exploitative. [My emphasis]

I personally find it very hard to view the modding community as it currently is (and has been for over 20 years) as exploitative because there is absolutely nothing obligating modders to create their work. I cannot imagine or recall any situation or dynamic where a mod creator was compelled to work for free by some system or power in the industry. Even when fans step in to create fan patches that fix games and make them more playable, they were not systemically obligated to do this. They did it because they want to. Virtually the entire spectrum of mods and modding culture is done out of free will by modders as a means to some other personal end they wanted. This is why I find this hard to accept:

Just as Facebook’s value as a social networking platform is created by the unremunerated affective labor of all their users, the gaming industry reaps the benefits of modders’ uncompensated work.

This is comparable to saying something like guitarists act as the 'unremunerated affective labor' for the guitar making industry. Sure, a good guitarist acts as an excellent advertisement for the value of owning a guitar in general but that doesn't mean that the guitar industry should be compensating guitarists for their 'work' in promoting the value of guitar playing.

Again:

Even more insidious is that many modders consider their work a trial run for jobs in the digital games industry.

Is running close to saying that an illustrator filling their DeviantArt profile with amateur drawings is an 'insidious' trial run for a desired career in the digital artist industry.