I think the answer is the total guileification of the (extended) GNU operating system. We need to facilitate cross-talk between bits of the operating system, and there would be no more natural way to do this in GNU than to make all commands understand literal Scheme lists of arguments, and give back literal Scheme lists of data (including the response to '(help), which would make the entire system introspective!), so that inter-operation between sub-systems becomes natural.