His "art" may not be to everyone's taste, but he evidently enjoyed financial success. I am reminded that Andy Worhol used to justify the (self-admitted) vapidity of his own work by pointing out its commercial value.
Now me, well ..... I prefer my own Master of Magical Realism. My "Painter of Darkness" - (the ironically named) Ivan Albright -
"Poor Room"
"Into the World Came a Soul Called Ida"
"The Picture of Dorian Gray"
"The Door" ("Also titled "That Which I Should Have Done I Did Not Do")
"Self Portrait"