How important can good (or bad) user interface design be? If the system you’re building is the Queensland Police’s record-management system, the interface can apparently be so bad that police would rather let petty criminals go free than try to enter an arrest report on the thing. In one case, the police found data-entry so time-consuming, they didn’t think they could get a summary of the case in time for a court appointment the next day. They were forced to release prisoners on bail.
In fairness, the article does mention that the new QPRIME system “replac[ed] 230 other systems, many of them non-compatible” — so the previous situation must have had its own disadvantages, as well. But whatever the new system’s advantages, if people can’t get information into it, it’s not going to be useful.
And the penalty for a bad UI in this case is more than just “the user might switch to your competitor’s product”. It can result in criminals going free and the police being unable to do their jobs.