Here is a message from his family
Pretty much any program I use I try to shift over to vim style keys. This guy’s reach went far beyond vim to me.
The hjkl keys came from Bill Joy when he wrote vi. The terminal he was using had arrows printed on those keys because it didn’t have dedicated arrow keys. It was a natural progression to reuse those keys for navigation.
vim was a huge improvement over vi. To where it became the defacto replacement. Some distros even shipped vim as a replacement for vi. That was because the Linux Standard Base required vi to be present.
Still a huge influence. vi was a bit painful to use when coming from vim. Would hjkl have died out if it wasn’t for vim? IDK. I think it would have been relegated to a niche corner of the unix/linux world.
The terminal he was using had arrows printed on those keys because it didn’t have dedicated arrow keys.
That terminal was also responsible for ~ used as home dir in path and ^ as beginning of string in regex.