You're the one who is obsessed with this subject. It just seems odd to me that you haven't really looked into it, otherwise you'd have some sort of opinion about where, specifically, people are prone to budget poorly. But I'll make it easy for you by providing a list of basic budget categories and you can tell me which areas you believe most people, who are not saving money, can feasibly make cuts to:
housing
transportation
groceries
healthcare
utilities
entertainment
other (crack, cigarettes, whores, etc.)
I've undoubtedly overlooked some important ones, but that's because I've honestly never made a budget in my life. I'm a cheap bastard and I can personally attest to the fact that even that has costs which might not be readily apparent to all: Some people find it fascinating, while others find it annoying and that incurs a social and societal price which, in some manner or another, translates into real financial costs. There's no simple calculus for this shit but you seem to act as though there is.