I don't understand anyone that want nj with mhj like even for artistic purposes.
There are two main reasons why that probably happens.
1. MHJ promoted the image of herself as the mentor of NJ so hard that for a lot of people MHJ=NJ and any criticism towards her is received as criticism towards the group. The same thing happened with BTS and Band PD/BigHit. Anything negative opinion about the company was considered an attack towards the group.
Another similarity of the two apart from the huge ego.
2. People simply love chaos or just hate Hybe that much. There are MHJ shooters here who never said anything nice about NJ or hardly ever said anything about them at all until this mess. People who would jump at any controversy like ETA and actually have and people who would undermine their popularity and scream payola when their new song dropped. But the fact that Hybe is involved gives people another reason to support MHJ, all the whole secretly rejoicing in the possibility of this mess negatively affecting NJ career somehow.
There are exceptions of course but for the most part that's why this is happening.