HTC has their reasons, what they are and why is for them and only them to know.
I've vouched for a multitude of changes regarding troops. Everything from specialized troops to destroy auto ack and other OBJ, to allowing more troops on C47 and LVT to be more accurate to the #'s they actually carried.
To this day it remains 10 troops per troops carrier ('cept the jeep), and 10 troops for capture. I'd like to see troops be a real concern. Being able to shoot just 1 of them and save the day for the defenders is a bit too easy.