It is pretty well documented that Gygax was keen to make enough income from his hobby to support his family. Despite Chainmail (with the fantasy supplement) selling 100+ copies a month, Gygax was disappointed with the insufficient return he was receiving.
Arneson, at that point, was only making pennies from the hobby as a result of his collaborations with Gygax. But, as he was younger and didn't have a family to support, it was less of a concern to him.
The money that Arneson received as co-author of D&D was only that which Gygax had agreed with him. That Gygax decided to try and freeze him out was Gygax's issue.
Whatever his motives, Gygax did tie Arneson into the commercial success of D&D despite the fact that Arneson really wasn't happy with the direction it took. If Arneson hadn't been tied in, then the launch of the publication could have seen it embroiled in bad feelings as Arneson and the Twin Cities crowd could have gone to far greater lengths to bad mouth it and Gygax.
Seriously, all of this has now been covered well in books. not sure why you feel the need to re-argue things incorrectly.
I'll bite, given that I wrote the OP (you did know that, didn't you) and that the OP was a specific response to Jon Peterson's book
Game Wizards, which documented this issue in great detail. But you know what- you joined on Saturday
solely for the purpose of commenting on this thread, so obviously your snark is well-earned!
Let's break down your points-
First, you seem to elide what I wrote- no one denies that Gygax was trying to make money. No, the point is that Arneson was trying to make money as well. What has been extensively documented, now, is how terrible he was at it. How so many people got burned in the 70s by trusting Arneson. How he repeatedly made claims that he had rules (and didn't), and how he repeatedly had other people do the work ("editing") for him.
Next, you seem to ignore what has actually been reported regarding the lawsuit. There's a reason I referenced Nimmer and the illustrations. It is somewhat impressive that a person managed to say that his game was nothing like what TSR put out, and also that everything that was completely due to his work. And, again, this is basic IP and contract law; the reason for the settlement, as was explored in the book, is because it happened at a moment of maximum leverage. - not because it was earned (it had to do with a contract that was poorly written, and, arguably, a poor decision by the judge early on).
Next, "whatever his motive ..." Dude, THERE IS AN ENTIRE BOOK ABOUT THIS. It has the contracts. It describes exactly how TSR was formed.
So ... maybe educate yourself before you comment? Here's a link-
Or ask your library to carry it. KTHX!