My understanding of the max zero fuel weight is to prevent wing bending. If too much weight is concentrated in the fuselage then the wings will flex dramatically in flight. By placing fuel into the wings, the weight is distributed more evenly, there is not a concentration of mass in one area.
MZFW is a design limitation, to increase this weight designers would probably need stronger and heavier wing spars and attach points.
BIK_116.80
I agree with you, if I saw your post I wouldn't have put mine up.
I just missed yours by 2 minutes.