You get what you (don't ) spec
Let's be clear on a couple of things here.
Firstly government departments are not victims: they employ banks of their own people to gather and articulate requirements, and to provide oversight and management of projects. Whenever a project goes tits up you must first ask what the buyers were doing.
Secondly, if you've ever tried to manage a project when the requirements keep changing, you'll appreciate that lining up a big team with a lot of contractors in such a way as to hit a moving target is a near-impossibility.
Lastly, it is true that consultancies make their money from 'change control'. I've even heard of firms bidding below cost, planning to make up the shortfall in the change control. But that takes me back to my first point - figure out what you want before you start building it.
Could well be that IBM dropped the ball, in fact probably did, but the Client had his day in court, so presumably had course to remedy.