This isn't going to be a very HN-like comment. But it's rooted in fact: That is complete nonsense.
For whatever it’s worth, the general stance of the project and most of the community is “git is good, we like jj more, but you should use whatever you prefer.” Lots of us loved git before jj came along, and there’s a lot of cross pollination between the two projects. I hope your parent takes the feedback and chills out.