Let me tell you why Roger Waters' music is not widely accepted. Waters songs are about real issues that evoke real emotions, and the truth hurts.
But there's a catharsis in feeling deep emotions while appreciating art. Everyone can empathize with the characters in Waters' albums. People really do care about the hypocrisy in government and industry, and the threat of our nuclear arsenals ("The Final Cut," "Radio KAOS"). And hearts really tear apart when relationships end ("The Wall," "The Pros and Cons of Hitchhiking").
Most people don't want to be challenged by their music to think about important, if disturbing, aspects of life. Music for most is an escape from the real world.
But for people who like their rock 'n' roll to be intellectually and emotionally stimulating, Roger Waters' stuff is about the best there is. Popularity is not necessarily a sign of greatness.