I agree that accessing the right networks will help tremendously, but I also believe that Sama's statement is accurate. One doesn't need pre-existing connections. This almost subtle, yet much more important condition was included shortly after the quote you mentioned: "If you build something good, people will help you."

A grand vision alone won't get someone nearly as far as it may have in the late 90s. A prototype that is nearing that vision with each quickly released new iteration seems to be the entry barrier for someone with no pre-existing connections.