Where is my Wikipedia?

Weeks ago, I edited the Namtso Lake post on Wikipedia. What I edited was based on my own experience there and some facts that every Chinese person knows. But only 10 minutes later after my edit, someone deleted my post. And he sent me a message, which said “I noticed that you made a change to an article, Namtso, but you didn't provide a reliable source. It's been removed and archived in the page history for now, but if you'd like to include a citation and re-add it, please do so! If you need guidance on referencing, please see the referencing for beginners tutorial, or if you think I made a mistake, you can leave me a message on my talk page. Thank you.” I thought this person has no idea and no background knowledge about what I edited. He only found that I don’t give some reliable sources, and then he deleted my edit. When I went to his page, I found he has done this kind of delete several times and many people gave comments to present their indignation about his thoughtless delete. I understand that Wikipedia is a place that everybody can edit, but I never imagined that there is this kind of person thinks he is the police of Wikipedia and unthinkingly deletes other people’s edits. I feel very disappointed and angry.