Common reasons in software system failure

A post by Charette in IEEE Spectrum on the failure of various government systems sums up pretty much the general reasons why they fail:

put all the blame for the fiasco on Deloitte, which Deloitte heatedly contests. News reports state that at least one Florida lawmaker is suggesting that Deloitte be barred from future Florida contracts, something that Australia’s Queensland government has done to IBM as a result of Big Blue's role in the Queensland Health payroll debacle.
[...]
The bottom line was that no one was in charge, vendors and the state did not get along, the vendors themselves did not get along, no one wanted to hear about the myriad significant technical risks, and political motivations dominated decision making. In other words, all the makings of an all-too-typical government IT project.

Could it be that we are trying to develop software to do far more complex stuff, instead of being a tool to help human, they are being developed to replace human? In many of these systems, the common theme in all these failures - hire more human to remedy the failure!

In most of these large systems development, by the time the system is ready, the world has changed; the political scene has changed causing requirements to change; rules are changing all the time before the ink is dried.