Yep, that's the canon reason. And the big Jockies, in their infinite rage, banned the puny SJs to LV-223 while they were on LV-426 playing with these cool eggs they discovered. Meanwhile, the puny Jockies were caught up in this whole "human creator" dilemma where they were mistaken for their larger, more vitamin enhanced counterparts, thus explaining the human/Engineer conflict in Prometheus.