The root of all evil in software development
Supposedly the answer is bad requirements. It is risky to take a radical stand and to isolate the determining cause to a single factor, but poorly conducted elicitation is surely one of them. From my experience, during elicitation, even with the best interest at heart, there is neither discrimination nor consideration for the terms requirements / solution design. This results in a cumbersome bundle of mixed information that doesn’t add up into a cohesive, unitary whole.