I don't know, I agree with original poster. No guide is "bad" unless they're saying something obviously ridiculous like "NEVER BUY ITEMS!" It's ok to kindly point out some flaws and offer your own opinion, but I too get pretty tired of seeing people downright tell someone that they're a noob because they don't personally play the champ that way.
People write guides because they know what works for -them-. If one style doesn't work for you, try another. It's that simple. If a guide really is worthless and stupid, then people will learn that by trying out the build and hence move to a different one. That's what practice games are for.
I prefer a community that feels comfortable offering advice, no matter how credible, rather than a community that fears even attempting to give some guidance because of opinionated jerks.
Trial and error my friends. If you don't like a guide, don't use it. If you really must say something, make it worth our while. Insulting someone doesn't get anyone anywhere unless you follow up with something rational.