The real reason is that if you give companies a budget feature, they will inevitably, you know, use it. They'll set a budget that seems 'reasonable', and then freak out when everything turns off when it's exceeded, and then go raise it a little bit, and repeat the cycle.
Compare that to now where every place I've ever worked basically seems to forget that cloud hosting costs even exist, based on how much most companies balk at paying for simple SaaS tools for developers but will happily let the hosting costs grow to astronomical amounts. They're happy to do it cause they just see a line item and accept it. If you give them budgets, that won't happen any more.
