The Oankali think humanity's fatal flaw is hierarchism plus something else, possibly intelligence. I am embarrassed that I do not remember.

I think my favorite Butler short story is "The Morning and the Evening and the Night" (or something like that; somehow, that title always trips me up).

I bought the short story collection and then Butler went and wrote another one. Luckily, it was legally available for free at some website, so I printed it out and stuck it in my copy of the book.