I may occasionally be looking for an app suitable to a particular task, and I'll find there may be a half dozen semi-"popular" options that I'll download and try, one after another.
If I'm familiar with the software's operating domain, I may expect that I can open the app and figure out how to get my task done in fairly short order. If I can't, I hope there are menus that may give me a hint. Failing that, toolbar buttons; but some employ mystery meat navigation, with no text or hover-tooltips to indicate what they might do, so you end up clicking blindly. Then you check for a "help" button or menu, and find there is none. You go to the website to look at the documentation which is broken up rather oddly, or it's a wiki that's almost devoid of content. If there's no generalized 'help' document, I'd hope the authors could at least create a document with a few screenshots / steps of the most typical use case.
After a while, you discover that figuring out how to use the app just isn't worth it. *CLICK*. Uninstall.