Z-Image is roughly as censored as Flux 2, from my very limited testing. It got popular because Flux 2 is just really big and slow. It is, however, great at editing, has an amazing breadth of built in knowledge, and has great prompt adherence.

Z Image got popular because the people stuck with 12GB video cards could still use it, and hell - probably train on it, at least once the base version comes out. I think most people disparaging Flux 2 never tried it as they wouldn't want to deal with how slowly it would work on their system, if they even realize that they could run it.