I don't think hos business planned sucked, as was said here. The exact same model has been used by others, but for very different products. I think the reason most people do not like his business is because he is selling bad paintings, but having a popular product and marketing the hell out of it is fine, as far as I am concerned. I still think he was a terrible artist. Would we be as critical of him if his product was an electronic device or piece of software instead of paintings?
The cost of art and who buys expensive art is indicative of who has the disposable income. A great movie showing excessive money and art is the movie Basquiat. When the economy booms, the oily art purveys come out of the wood work.
Those motivational posters make no claim to be anything other than what they are - disposable decor. And they're generally priced accordingly. And I have zero feelings toward the person(s) who invented them and made millions of dollars selling them. They're NOT art- they're pretty propaganda. If you want to envy someone, the successories people are far more enviable because what they did is at least honest. Nobody buys a "TEAMWORK" poster thinking that their grandkids will be able to retire on the sale of it.