[moftz]

It's cheaper for contractors to slap together a bunch of COTS stuff and get good functionality for a "low price" versus building the perfect system from all-in-one designs. The manufacturers aren't going to make military spec all-in-one components because the military isn't buying that much compared to the commercial market so the manufacturers aren't going to invest the time and money into something that isn't going to sell volume. Even if they would make these parts, they are going to cost a lot more than what it would cost to design a slightly more complex, less integrated system. Everyone is better off with more general parts. More components in a system also allow the designer to swap portions out for newer designs as time goes on where as an all-in-one design is going to require a lot of NRE to update.