"So, what about the G2 figures? Why hasn't anyone in the community (besides RDNA and a selected few others) taken the time to work on them?"

Because they suck.
Plain and simple. They suck.
The abdomen and the buttock bending is miles better than V4's but their ellbows, knees and shoulders are afwul.
The mesh is bloated, their are no "official" morphs, and
besides MIKI 2 the bodies and faces are horrible,

Sydney is just a "Vickyfied" Miki, while Simon, well, I really don't think any mesh deserves to look like Simon.
I mean, James I looked AWESEOME, and then they morphed him into Simon and James 2.
Same with Koji 1. The most realistic looking male Poser face EVER, and they ruined everything.

You think I "hate" V4 and DAZ ?

Nope. Ever since Posette the owners of Poser managed to drop the ball MASSIVELY.
They made the first "complete" Poser woman, and they were obviously so ashamed that they made her as ugly as possible so noone would even WANT to play with her extra parts.

And I still wonder what they were smoking when they OK'd Jessi and the P6 kids.