Hey, I'm not saying the reputation isn't deserved. It totally is. Almost everything coming out of that wiki is rank garbage that makes Dragon Magazine look tame and balanced by comparison. But because it's gotten special callouts for super-ultra forbidden-ness, even in otherwise painfully permissive games, it gets a callout here.The usual issue with Wiki stuff is that careless players find it on the Internet and assume it's official rules, rather than something anyone may have written. This definitely gives me as GM a prejudice against it, I get tired of having to google the source of some unlikely stuff. It's too much like my day job teaching!
As I said, a lot of attitudes of this kind--e.g. "core books only" and the like--cropped up particularly during 3.X, and have lingered since, shaping the overall zeitgeist of play. I can't tell you the number of conversations I've had that could've been solved by someone not presuming a hierarchy either literally the same as the one I listed, or a sufficiently close equivalent as to not make any difference.