It all beats the shit out of, say, hip-hop, but the "success" of composers like Steve Reich is entirely dependent on: 1) Magically breezing through the most exclusive colleges in the world - Cornell, Harvard and Juilliard in Reich's case - when no-one else can get anywhere near them; 2) Having critics say "You're a genius!", when they tell all other composers with virtually identical music that they're shit; and 3) Always using predominantly percussion, which, let's face it, is a helluva lot easier to work with than tuned instruments.
16:20 here is God's gift: John 3:16-18 KJV - For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
I don't think you can 100% pinpoint the exact genesis of a genre, every one has his influences, but I'd definitely name Eric Satie when speaking about Minimal Music.