This seems to strike a good compromise as "third party" commands are "lines" type which is basically what we are used to send and receive in unix tools. Of course a lot of tools already support emitting JSON so it seems the Crush is already more useful than the typical unix shell as you can still use "lines" for every program (and convert to a table by parsing if you want to use the more advanced features) and there are already a number of third-party programs that you take directly take advantage of these feature with even though they didn't know anything about this shell.

I think the fact that you can already use this with most programs and it is never less powerful than bash seems like good indication that the system doesn't need to be reworked around this shell. It fits in cleanly to existing paradigms.