More Words, Deeper Hole

Yes, early on there's the speech about how some job can be found for anyone, no matter how limited their abilities, but once Rico is in training it's all about he survives when the big talkers, would-be tough guys, etc. fail. The way I managed to reconcile that in my mind is that the system decides what opportunity to offer a person based on their assessed abilities, and then they get their citizenship or not depending on how they do with that one chance.

Stepping back and considering the existence of the author, I think maybe Heinlein set up the society so as to answer all objections to it, and then got too worked up about writing a manly-man military adventure novel when he got to the training section.