Because of his self awareness and compassion for all sentient beings.
George Harrison introduced the mainstream music listener to what is now called World Music. Through the Sitar, he broke the barriers of using traditional eastern instruments in western music. Harrison was also the first to organize the all-star concert to help aid victims of political/natural disaster with The Concert for Bangladesh, putting the crisis on the world map. Additionally, Harrison changed the way AID was distributed to victims- paving the way for Live Aid, Farm Aid and others.
George Harrison's Concert For Bangladesh was the first major benefit concert that brought awareness to a world problem. This concert led the way for future benefit concerts (i.e., Live Aid, etc.) and had an influence on future artists (i.e. Bono, Michael Jackson) to get involved with causes.