A lack of art education, inexperience in seeing, and a general aesthetic laziness, will lead to the glorification of the trite, the cliche, and the kitschy.
I understand that a lot of the Bob Ross revival is "ironic" and nostalgic. His teacher and predecessor Bill Alexander, even though his pictures looked similar, didn't become iconic; he didn't have the funny hair, calm demeanor, and catchy phrases.
He may have been a really nice person, but man... his paintings make me almost physically nauseous.