I agree that it's perhaps not the most robust choice, but at least for my field (bioinformatics) it's a good balance between accessibility and performance. That being said, in most cases when I come across a paper >1 year old presenting the latest-and-greatest Shiny web app, it is wholey broken when I try to use it :|
Is it because they stopped paying for Shinyapps.io? Or they exhausted the free usage monthly quota. In my experience these are the common reasons. If they did not update the app, there is no reason for it stop working. I have apps running fine and they were created 3-4 years ago.
