It's all conjecture unless someone who was involved & responsible for the decision can comment, but:
The '71 seem grille - and tail lamps - seem the most expensive to make, and Chrysler was generally always trying to cut costs.
Yearly updates, and several treatments being designed, likely contributed to '70-'70-'72 facelifts.
Personally, I like the '72 grille & rearend treatments the best, and feel the '71 is indeed a bit heavy on decoration.
But I wouldn't be likely to kick one of any year out of the garage.
I like that folks have their own favorites, as I've said many times before; it would be boring if we all liked and drove the same thing.
I'll try to get a comment from some old retired Chrysler guys. Personally, I MUCH prefer the styling of the 1970 to the 71. I thought the design of the 71 B-Fishes were too busy compared to the clean styling of the 1970. I absolutely love the front parking lights on the 70's, and the whistle they made when driving by.
