I can understand where they are coming from with their "we want potential captains" recruitment policy.
Aside from the practical issues of wanting people to move up the ranks, and fill the command slots, you also would not want jellyfish F/O's who are unable to assert themselves if faced with a captain about to make a mistake, or not up to par.
Personally, I wanted nothing more than to be a CX captain. And being a captain when I joined, I enjoyed the role.
But several years in CX has beat that out of me. Now I just want to salvage a decent roster, and keep my stress to a minimum.