The mainstream audience was young and open to new ideas. Folks could create new things that impacted the culture at large and in that way punch above their weight class. In NYC, people could create art movements that would live for the next 50 years. Sort of like the way kids could create new technology in a garage in Silicon Valley in the 70s, or a dorm room in the 00s. It was a time in culture where the doors were open and you could have profound impact. The doors closed again, so people look back and have an appreciation for what was possible and what became and perhaps long for it again.