You should blame them for taking the money, because they "take the money" specifically by acting in bad-faith in order to extend, extend, extend and extend the contract money flow into their coffers. That's how the system works: private, for-profit companies fuck things up, intentionally, and then because they are the experts on the system they fucked up they (practically) automatically get the (almost as lucrative) follow-on extension/"fix it" contracts. The "bad design and architecture" these for-profit companies come up with are a feature. It is intentional, and it is done intentionally because these for-profit companies aren't in the business of providing products and services for the government--they're in the business of needling more contract cash out of it.

Or, to put it another way, you can't cry foul at the government's waste of money when it is the contractors' bids and bad-faith implementation of the contracts pushing up the costs. In return for their efforts, their liaisons at the government get to keep their visibility on "important" projects high, and extend the life of their own jobs.