Bedrockgames
I post in the voice of Christopher Walken
To be blunt, it doesn't matter what they agree with. The definition of literature is anything written. Period. That makes RPGs objectively literary as they are literature. Those who object to calling RPGs literature can also object to calling Earth a planet, the sun a star or that diamonds are hard. Those objections are irrelevant to the facts and reality.
There is a lot wrong with this, and we've already gone over it many times, but just to focus on the point most important to your own argument: the reason this is a big problem is because your point doesn't just rely on meaning A of literature (written works), it also relies on meaning B ( especially those considered of superior or lasting artistic merit). This is the equivocation I have been talking about. You have been repeatedly relying on A in order to assert that RPGs should have some kind of quality in the descriptions (which is more a part of meaning B). You need to prove both A and B are the case with RPGs in order to make your argument. You can't just get by trying to make a case for A, and then equivocate with B.
Also, and this is really, really, really important. The 'especially' part of that definition is not insignificant. It matters a great deal.