Isn't it selfish for Abnegation to allow the Dauntless to go out and die in defense of their borders?
But wait, wouldn't it also be selfish to not let the Dauntless do what they're good at, to take that away from them?
You can't define "selflessness". Sometimes it contradicts itself, and frequently there's NO WAY to make a decision that isn't somehow selfish. If both forks in the road lead to selfishness, what are you supposed to do? Kill yourself, rather than be selfish?