The Sigil said:
I didn't say that was the reason that GAME COMPANIES exist.

I said the purpose of a RPG publication - i.e., the tangible book (or e-title) itself is to aid roleplayers in entertaining themselves.
I stand corrected. Partially.
You did address the role of the publication, the physical object. However, I don't agree that in all cases the purpose of the publication is to aid roleplayers in entertaining themselves. The purpose of the publication is to earn money for the publisher. Sometimes the publisher means it to be an aid, sometimes they don't.
Thus, the "highest purpose" of a publication (the thing itself, not the company that created it) must be to enhance the enjoyment of the role-players, else the entire thing falls apart because the gamers stop spending money and the publisher collapses.
In a world where the publishers and the gamers act in enlightened self-interest, with full and open knowledge of what other gaming materials exist, this may be true. But again, you wander into the mystical nationof Theory. In our country of Reality, things are not so simple.
Take late-stage TSR as an example. As I understand what Mr. Gygax has reported, TSR was not killed by bad products. It was killed by some upper managers who had no interest in running a game company. They wanted to earn a few bucks off the thing, and then toss it aside like an empty Capri Sun drink pouch. This meant that TSR published a number of books whose purpose was really to earn a few more bucks before the managers jumped ship.
The gamers, however
continued to buy this mediocre product. In its day, this stuff still sold well, realatively speaking, and was influential for the game and gamers everywhere. But it is now widely recognized as mediocre product, at best. For quite some time, TSR continued merely on the strength and loyalty of the fanbase.
In theory, a gamer should pick and choose his materials carefully, and only buy those that are good, and cease buying things from publishers who consistently create poor products. But, many gamers don't buy out of informed, thoughtful, enlightened self-interest. Some buy materials like some players buy Magic or Pokemon cards. It's new, it's official, therefore it must be purchased, period. They don't thoughfully weigh it against other similar products. They may not even know other products exist! You still this sort of behavior in gamers today who refuse to play with anything that is not "official", and gamers who buy anything published by a specific publisher, whether they need it or not, whether the product is good or not. Gamers who refuse to even try games by publishers they've never heard of before, and so on.
Sometimes, even when the publisher is acting out of enlightened self-interest, the purpose of a product is more to earn money in the short term than to entertain. Some third-party publishers run on a hair-thin budget. They have bills to pay, and if the next thing in the pipeline needs a lot of revision because it isn't good, that's just too darned bad. If they delay, their debts catch up with them, and they'd fold anyway. Better, then, to ship out a mediocre product to earn money now, in the hops of being able to cover the bills and have the next one be better.
Sometimes, even a gamer acting in enlightened self-interest buys product that isn't so hot. They dont' have a chance to fully review the material in a store. They glance at the cover, and a bit of the interior, and make a quick decision to buy without fully knowing what they are getting. They get it home, realize that it is mediocre, but are not upset enough to return it. It sits on the shelf unused.
However you slice it, the world ain't perfect.
You may not agree with that, but that's my opinion and I'm sticking to it.
Sorry. While I'm basically an optimistic person, I'm not idealistic enough to think that our world operates as if it were an Ideal, Well Informed, Free Market System, where there are no barriers to good products and bad products always sell poorly.
You seem to argue about the way the world
should be. I'm talking about how it actually is.