Linus also had the internet. Look at rms' signature - UUCP, ARPAnet. The internet, usenet and the patch program made collaboration much easier.
People weren't really clamoring for Hurd or a kernel for GNU, because they got an OS with their computer, and got the GNU tools and libc. The really major geeks would buy old, used workstations, which were built like tanks and were plenty fast for running single-user unix.