Why do people say self publishing isn't as good as publishing a book with a company?

[Phantomnest528]

Self-publishers will take anything that a writer pays to print. With a traditional publisher, they only publish works with a very high quality of writing and storytelling; that standard does not exist for self-published works and a self-published work does not need to be edited, reviewed, or even completed or factual to be accepted by a self-publisher.

Self-publishers will not help you sell your book--they've already made their money from printing the books. It is completely up to the writer to market, advertise, and sell their book. Many bookstores will not stock self-published books, as per the first point, there is no guarantee of story or writing quality from self-published works.