Wikipedia simply gathers information from various sources (e.g. websites, books, journals, magazines etc.) and presents all the information in a concise form. Do not blame Wikipedia for unreliable information, blame the sources Wikipedia is quoting from. Note: Wikipedia usually chooses the most reliable sources, so it is unlikely that you'll find any source on your own that is more reliable than those which are already being used on Wikipedia.
I agree that it is foolish to actually write a paper and cite Wikipedia as one of the sources because that just makes the writer look like extra lazy. These people fail to realize that Wikipedia has its own citations too, which you can just copy from.