But ignoring two out of three things in order to talk about the third is better?
The point being, it's not totally unreasonable to expect a basic level of knowledge about something
before pontificating strong opinions about it. Or, at least it's not unreasonable to expect people to keep an open mind if they don't have a basic level of knowledge on a subject.
As far as "I should only need to read the rule books" goes,
@Faolyn, that's not really going to wash in Dragonlance (although it does in other settings) because, unlike other settings, Dragonlance didn't start as a boxed set. The setting guide came out years after the modules and the formative novels of the setting. And then we got three or four massive rewrites to the setting after that. Which of course does make conversation really tricky.