I think why it works on the PoF (and by proxy, Ekimu) is because it works with the chest in terms of smooth contours. The 'moobs?' on him give it a nice and sleek look that complement the legs, in terms of armor placement.
I'm an agreement, though, the articulation is junk, and quite misleading in terms of packaging art. And does hamper the toy as a whole. The combination of mediocre weapons, short arms, as well as the leg construction should make the PoF a bad toy.
However, He is my favorite from the six because of those factors. Its hard to explain, but if I just stare at him on my desk, he carries a presence that I feel none of the other protectors carry. PoE comes close, but the gattling gun chest breaks up the smoothness that the PoF has, and his leg construction complements that.
I'll defend Gen 2 Vakama for very personal and aesthetic reasons, but I also cannot ignore with your points, Var. In fact, I agree with you. I do believe that in the end, the Protector of Fire makes a case of being unique that doesn't revolve around different armor placement or colors.