Why do people hate wikipedia?

You say in your question "anything online can be made up and untrue". While, to a degree, this is a legitimate claim, it doesn't hold water in practice. The reason? Libel and misrepresentation laws.

Websites that actually publish copyrighted information that is presented as factual are ACCOUNTABLE for that information (and subject to a tort being filed against them by any aggrieved party).

Wikipedia, on the other hand, hides behind an out-of-date protection offered by Section 230 of the 1996 Communications Decency Act. By claiming that they are not actually the "publisher" of the information, the Wikimedia Foundation is immune from prosecution, so they really have no care or reason to assure that the information is actually accurate, in the same way that a newspaper or a commercial encyclopedia would strive to be.

So, I'm afraid the premiss of your question is a bit off-target. People "hate" Wikipedia because it is protected by a law that enables it to be the world's most irresponsible encyclopedia.

My teacher is totally against it. I just don't like it because it has too many words xD But she says that anyone can go online and edit it. So apparently its "junk". So, I think that it is not a good source for valid information.

Well, I've been on that site and, it gave me wrong information.

Yeah, I didn't get in the newspaper because of it.

So, I got pretty mad.

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i dunno i dont hate it or anything and yeah it is editable xD