> ...he is essentially as narcissistic as the newcomer is by accepting all new contributors without setting expectations.

But the whole point of the article is to explain why he does not do that!

Setting expectations is no panacea. A non-trivial fraction of volunteers will nominally accept the expectations but do what they want anyway. Another non-trivial fraction will also accept the expectations but then go along with anything those of the first group suggest.

These are universal facts of organizations of any type, not just technical development teams.