Yes they are. I am. Many other people are too.

git was a great step forwards, but its conceptual model just doesn't map well to a lot of workflows, and some very simple things are very difficult or impossible with it. It was designed using a certain set of assumptions and primitives, and other assumptions and primitives turn out to be much more suitable for certain workflows.

I don't know if jj is the perfect answer, but it's a huge step forwards in many ways.