'nothing' = massive generalisation.
For instance, one can't go into marketing (well, be a good marketer anyway) without having studied a marketing major. The people who go into the business without having completed at least a minor tend to produce really shit campaigns (often I'd see something in Adnews and go 'wtf. thats retarded (it doesnt work because of a or b or c, theres no consistency with d)' the person responsible for the campaign doesn't have the accurate qualifications.
Accounting - how is that irrelevant? i don't do it but I'd imagine that it'd be very necessary.
I could go on.