I understand what you're saying, and I think it's a really good instinct.  The hole for me is, it's a management command--it can be run from the command-line, and should be valid to be run that way.  

From an interface point of view, I'd expect this command, run from the command-line, to update with the current language if nothing was specified.  I'd even expect that if this was a function.

Not a biggie, do as you like--just describing my thinking process.