JSF programme grossly over budget at $1.8tn and the Pentagon ask for another $500m. They can't guarantee clean water to all but shiny new military-industrial-complex toys? Hells to the yeah!
I understand things like this go over budget and time but how do they consistently get it so wrong?
$1.8Tn is the air frame life cost (40+ years). $500M over that period is tiny in comparison so I'm not really sure what you're point is there. Overall life time cost forecasts for the JSF have actually decreased, and will continue to do so (LRIP9 lot price is ~4.5% lower for example)
When thinking about cost/schedule increases people need to consider just how complex these things have gotten now.
The JSF programme was always going to be the largest single acquisition defence project in history. It involves numerous partner nations working under agreements that are the first of their kind. All of the technologies are brand new, even the materials and bolts at the lowest level.
Small estimating errors by the sub-tier suppliers compound all the way up to the top, which when combined with unforeseen technical issues and unclear/changing requirements on such a large/complex project give you the current situation. We've all seen these things happen on small projects, now try and scale that up to $2Tn!
The variances on big number projects are always going to be, by definition, big. 1% of $2Tn is massive, especially if considered out of context
Doing things at the forefront of technology and innovation has never been cheap. But for some reason the JSF gets an unjustified amount of bad press for it.