If he had 20 more years, TEN more years! What could he have dine? Would we have seen his Epcot? It needed him and Roy if it was ever a reality... People needed them as the spearhead before they would back the city.
Walt Disney had talent, imagination, and courage. All 3 with Roy's talents and faith in "the kid" changed the world. A few more years, and what would the world be?