I don't blame btcltcdigger for quiting bounty managing, I heard that many bounty hunters don't care much about bounty managers this days, they act too mean to popular bounty managers like bubbalex, btcltcdigger and others, it's not just about how hard it is to manage bounties, it's more than that
You are comparing two disparate bounty managers, btcltcdigger has not had any successful projects in memory (I may be wrong, but these will be isolated cases). As for bubbalex - I talked to him, he says that he will take a break from bounty campaigns for the time being.