Why is Wikipedia not a credible resource?

As a student who can be very tempted to click on the Wikipedia links when researching for an assignment I can for one say it is not a credible website. I do agree on researching on Wikipedia for a basic understanding of whatever topic someone may be studying, a good foundation but one that need to be built upon with many credible sources to back it up. As said by Harvard’s student president; “There’s nothing more convenient than Wikipedia if you’re looking for some quick information, and when the stakes are low (you need a piece of information to settle a bet with your roommate, or you want to get a basic sense of what something means before starting more in-depth research), you may get what you need from Wikipedia. In fact, some instructors may advise their students to read entries for scientific concepts on Wikipedia as a way to begin understanding those concepts.” (Harvard, 2014). To then follow up from why it is only good as a beginning point, from my own personal experiences, I, myself have changed a Wikipedia document. I then check an hour later and the false information I had written was still there, I checked the next day and it had been taken down. IN saying this, yes the false information was taken down but it was still up for a certain amount of time. I believe that Wikipedia is not a good source for students as stated before in university assignments it is important to have peer-reviewed sources that are credible and in which I will receive the correct information from.