I don't know, Kinkade pricing mechanism allowed regular people to be able to afford his paintings. there is something to be said for that.
To be fair, his original paintings were never affordable. He charged outrageous prices for them, far more than they were actually worth, and never really intended for them to sell. This is the "scam" he ran, in my opinion. What you were actually buying in his stores was a print of his painting. They used texturized undercoats to make the print look like actual paintings. As long as you didn't hold a magnifying glass up to one to see the printed dots, they were extremely convincing as original oil paintings. So many people thought they were buying actual Kinkade paintings, when all they were really buying was a high quality print. Some of the sales people in his stores were more honest than others in disclosing this. My parents actually bought two before a third salesperson finally divulged the truth. Needless to say, they were upset when they found out. Their prints are now only worth a small fraction of what they originally paid. He kept his originals artificially high to promote the value of his prints which were the real bread and butter of his industry. Now I don't think he intended to fool people into buying his prints thinking they were originals, but that clearly did happen, and I'm sure he was aware of it, and he didn't really take strong precautions to stop it from happening.
Lots of artists have made a good bit of money selling prints. Dali and Picasso sold tons of them. But the works they sold as prints were only ever available as prints. They were never copies of original paintings (at least not intended confused with original paintings). So they still had value outside of the gallery because the plates were created by the artist's hand. Today, they're still considered original works and not reproductions, despite existing in numerous copies across the globe. And they were available at the time (and in some cases even today) for a reasonable price. So if it's your dream to own an original Picasso, you can still purchase a signed print for under $1,000. And these too have the potential to increase in value (though conservation of a print can be expensive and they are getting up there in age, so it might not be the best example of an investment in the art world).
Isn't it true that most of the great artists of the past were what we would today call commercial artists, or in other words, someone paid them to make their art?
Prior to the Renaissance, yes. And the church was more or less the only patron. But the Renaissance was when the artist started to break free from the patron and create art for the sake or art, and not just for the sake of money. It was a long and slow process, but by the 19th century, most artists that we know of today were free to do whatever they wanted and sell to the general public. The idea of painting for the sake of painting really took off for Impressionists. By the time they came around, making art for the sake of money was kind of shunned. This is also a large reason why their works remain so resonant even today. A painting of a portrait doesn't appeal to as many people as a painting of hay stacks or water lilies.
These days, it's a little more balanced. Most artists will take on the occasional commission, but generally paint, sculpt or whatever, without a commission. For instance if you look at the work of Keyhinde Wiley, you'll notice the majority of his subjects are regular people who could never afford one of his paintings. They clearly didn't commission his work, as they don't own the paintings he made of them. Though there are several portraits he's done of rich and famous people who were clearly commissioned, President Obama being the most famous. Galleries have largely removed the need for taking on commissions, though there still exists artists who work strictly on commissions. You likely won't make your way into many museums doing corporate art, but you can make a pretty decent living at it. Though I say that, and I have a friend who solely does corporate art and he's actually designed quite a few displays at museums! So while he might not have his name featured on any artworks in any museums, he definitely has a lot of museums showing his work!