Switching costs. They already owned the old version, having paid for it and installed it in their home. The issues were a minor annoyance but the effort to fin

Switching costs. They already owned the old version, having paid for it and installed it in their home. The issues were a minor annoyance but the effort to find a new one and risk it being worse was far greater. However software, especially web applications generally have a low switching cost. So while your application might fulfill a need if you don't fix the annoyances you make it all the easier for a competitor the sweep in a grab your business. The history of the internet is littered with examples both large and small.