Just is built in Rust rather than C. Rust is generally nicer to work with and maintain than C libs so huge win there development wise. Feature wise, only see a couple things with Just right now that differentiate it from Make.
When something doesn't work as expected, I dive in as deep as the rabbit hole goes to get across the line.
Curious what led you to arrive at "Aha! They must be an ops person", will you humor me with an explanation?
It is possible to reimplement a relatively easy tool like make, and having learnt from its historical shortcomings it can be better irrespective of the implementation language. But that’s a different point.