If it was for technical reasons, so beit. I'm assuming it also has to do with the shorter runs of cable to the charging system for such high voltage/amps SC charging.
More copper, more heat too.
I'd would also trade a larger frunk for a front charger, it that was consideration of the placement in the back.
Ideally, a port on each side would be better than just the one. Maybe this could be implemented within the current designs? Doesn't the second charger on Model S go on the right side?