Not really, no.
Let始s imagine a world around 1995 where open source hasn始t happened. There was little Gergely and a friend of his. We used DOS (proprietary) to play (proprietary) games, and also used QBasic (proprietary) to write small programs. We shared the code between each other, and later with some other guys who also tried to learn programming.
We knew nothing about development. We never heard about open source (although we also haven始t heard the term proprietary). Yet, we already did open source, as we shared our code without expecting -beer- chocolate in exchange.
No. Given the nature of a big part of humanity, I don始t think a world without open source is possible. It might be labeled illegal, but it would totally exist.