Dude... an argument can certainly be made that English evolves by consensus; you're right about that. At the same time, that doesn't mean anything goes! It perhaps would be going too far to say that something is "correct" or "incorrect" English. But we can certainly give a proposed fragment of English a score measuring how well it matches the current consensus regarding what is a valid sentence in the language. Now,

> while others' poor experience is a result of their more layman writing style.

would receive a low score: "Layman" is not a noun commonly used as an adjective where common is relative to the overall usage of "layman".

The adjective is "lay".