an interesting point of view is that if facebook had made an ICO they would never made it through anyone diligence nowadays and yet there he is coming from his rented Californian house a nobody computer science harvard student creates a multi billions worth corporation with 2Billion users database.
following 2018 ICO strategies diligence, facebook would fall in the scam ico ;-)
It's useful to give a baseline, but not intended as an end all, as with anything else.