If this is all about fair and why we do care about gambling? I think for others they always care if the site is provably fair or not because they are just wasting their time while they are playing for nothing.. but for others they are just gamble for fun not making any profit they are ok if they are lose a lot even the site is not provably fair but for me we need always to check if its if provably fair or not that is why we are care about fair.