Maybe people don't know how to open it? Some websites exactly show users where to find the download afterwards. With Firefox, downloads pretty much disappear. I

Maybe people don't know how to open it? Some websites exactly show users where to find the download afterwards. With Firefox, downloads pretty much disappear. In Chrome they're a bit more visible but easy to overlook. You could also trigger false positives with antivirus software preventing users to open it. There are a lot of reasons why users might click download but don't install or run the software in the end.