Why aren't the answers on this site correct?

Answer 1

Because they're answered by volunteers. You want a right answer, hire a consultant and expect to pay through the nose. You want an answer for free, you take what you get.

There are quite a few volunteers who go through and remove some of the more egregiously wrong answers, but they can't catch every one, and are more likely to spot answers that are clearly, obviously wrong (especially if it's not only wrong, but completely incoherent) than those where the flaw is more subtle.

You can kind of gauge the quality of an answer by a couple of factors:

Answers from people with names (as opposed to just IP addresses) are somewhat more likely to be correct. This is especially true for contributors with high "trust ratings'. However, "even Homer nods," and a high trust rating is not a guarantee, especially since someone who has a high trust rating for answering Pokemon questions correctly is not guaranteed to know anything at all about physics and vice versa. Named contributors will often have a bio page that can give you a little more information about them ... though, again, there's nothing stopping some crackpot from claiming to have a doctorate in something (and no guarantee that an advanced degree means they're NOT a crackpot ... there are plenty of well-credentialled people who are infamous in their field of study for having off-the-wall theories).

An answer where the spelling and grammar are correct, and where the reasoning behind the answer is shown, is somewhat more likely to be correct than one that is misspelled, ungrammatical, or simply a short "yes" or "no." At the very least, showing the reasoning allows you to see whether or not it's ... well ... reasonable.