About JCMs:

Weightmapps and bulgemaps can only get you so far, as they both can move a vertex only "in" or "out" in regard to the joint center.

A JCM fix morph can move a vertex into any direction you want, so the joint can have any shape you want.

You can get pretty far without a JCM (Both V3WM and D3WM don't use JCMs for their shoulders as I wanted to see how far I could push the limits), but if you want 100% accuracy, they are a must.

Also if you want your figure to be capeable of extreme bends.

V3WM and D3WM can cross their feet behind their heads, and despite careful weightmapping, the only way to make them do that without their rear ends exploding was to add a JCM to their butts.

It takes just a couple of minutes to make a JCM fix morph using ColorCurvator's MorphLoader or GoZ and to set it up using the Dependency Editor.

You have to decide for yourself if that added realism is worth those few extra minutes for you.

(JCM morphs are injectable, btw, just like any other morph)

 

So, nope, JCMs are not a "kludge" or "sloppy rigging" that should be avoided.

It is a tool that gives those of us who prefer 100% realistic joints the edge over those who set different priorities.