Not going to comment on the wing chun striking rotation but you have oversimplified the boxing rotation. While a jab or a cross may have separate shoulder and hip rotation close in strikes like hooks, shovel hooks and uppercuts utilize a shoulder hip alignment for power.
Boxing does not lock itself into one way of throwing punches.
Look at the pivot of the left foot when throwing a left hook. Hip, shoulder and body weight all in one synchronized motion.
You can make any statements about wing chun striking you like and argue about how its done, but if you are going to make comments about boxing punches please try to get it right occasionally.