Edit: I think what may motivate BCX is defeating overconfidence.
I don't think the devs have been overconfident at all, on the contrary. Maybe I am. But what is BCX's problem?
You apparently forgot that Risto predicted in public only a 4 - 8% chance that BCX could attack.
Perhaps you've forgotten fluffypony's confidence upthread, he said basically until there is an attack there is no attack and he is going to the beach.
OTOH, some of the developers have been openly concerned, such as smooth and NewLiberty have tried to investigate and implement improvements. Perhaps fluffypony did too behind the scenes, I am only commenting about his public demeanor in that one instance.
I know xulescu addressed this as a misperception, but how can something that happened after the announced attack have contributed to the attack.