Carmack is...a special case. The reason why being blindingly fast in tmux/emacs/vim/shell/etc. is a difference in kind rather than degree is because it lowers

Carmack is...a special case. The reason why being blindingly fast in tmux/emacs/vim/shell/etc. is a difference in kind rather than degree is because it lowers the activation energy on trying radically different things. If you can move massive amounts of code around quickly and accurately you can try a different design on a whim, and throw it all away without a second thought if it doesn’t work out. When manipulating code is time consuming there is a tendency to “make it work” with the design you’ve got. So much code looks like someone “made it work”.