If you're right, I would say you're making a pedant argument. If you're wrong, I would say you're making a pedantic argument.
And, fine, let's call it an attributive noun rather than a noun used as an adjective. I was taught the noun as adjective thing in high school but happy to update my terminology. Indeed "layman" is not on my list of acceptable attributive nouns.
Did you notice how your first link says it's "incorrect" to use Kyoto as an attributive noun?
Of course it's not incorrect to use Kyoto as an attributive noun. "Kyoto accent" is perfectly correct. The "rules" laid out in that link are more like common patterns, not prescriptions.
Hard lines rarely happen in the real world. It's best to be flexible such that you can accept unfamiliar instances of familiar patterns without trouble.
I'm certainly disagreeing with the part that claims there is an explicit list of correct uses. English isn't that simple. They were cited as a big list of examples, not as having all the rules.
And, fine, let's call it an attributive noun rather than a noun used as an adjective. I was taught the noun as adjective thing in high school but happy to update my terminology. Indeed "layman" is not on my list of acceptable attributive nouns.
Did you notice how your first link says it's "incorrect" to use Kyoto as an attributive noun?