Eh... Wikipedia is only a reliable and precise source if you have the level of Media Literacy that allows you to question various sources for reliability in a decent manner.
So... if you are dealing with a Dunning Kruger level of inability in the area of Media Literacy... saying it is not a reliable source is kind of true. Even though the current stance should not have you able to make accurate statements about reliable sources. It is a really weird form of coincidental urban mythology with relevant reality. As the urban myth is true for the cases of people spreading it--but people not spreading it, there is a chance that it is not true, due entirely to levels of competency in Media Literacy being the actually source of said Myth.
That being said... Wikipedia DOES exist in the same area that if you can properly handle that being reliable... you can also properly handle the Weekly World News as being reliable. As you are going to spend more time looking into the sources, what is being referenced, how accurately it is being referenced, any possible misinterpretations, etc.
The issue comes mostly from when you are not spending most of your time going to the sources being citing... anything is about as reliable of a resource as the rags Rupert Murdock is in charge of.. the only difference is that Wikipedia does not have a page 3 girl.
... wait... I've just got a BRILLIANT[LY TERRIBLE] IDEA FOR A POSSIBLE COMPETITOR TO WIKIPEDIA! The website that is too big to take on rationally anymore... it involves a similar repository of information... but I also have a Page 3 Girl on it.. or just have all the pages done like it is a Page 3 Girl saying it all! Yes! I HAVE NO REASON TO THINK THIS IS SOMETHING I COULD EVER REGRET! NO WAY THIS COULD BACKFIRE IMMENSELY!