Because we all remember Michael Jackson for his cinematic excellence in The Wiz and Captain EO?
George Carlin was in 16 feature films, including a film nominated for best picture (The Prince of Tides) and a film nominated best animated feature (Cars).
No offense, but Michael Jackson was bigger than all the people you mentioned; maybe not recently, but if you said have you heard of Michael Jackson or Bea Arthur, I bet you that MJ would come out on top...
George Carlin in cars = voice-over, not acting...
George Carlin in prince of tides = never saw it so I can\'t speak to it... But doesn\'t look like a movie I\'d watch anyway... Streisand = change the channel...