Ok, that's a bug; it may just not be implemented yet. We can fix that and perhaps try to be clearer about Juno.jl's role as an package.
I agree 100% with your take on RStudio and others. The thing is that while IDEs like RStudio make it look easy – because they are great pieces of software developed by big teams over many years – the level of effort and polish needed increases exponentially as your users get less technical. There are just hundreds of small trip-ups (like this one) and that takes a lot of raw dev hours to get right.
Right now I think we're in a position where Juno is great for mid-to-advanced users, in particular package authors. We really do want to serve the less technical researchers; I think that we'll have all the main IDE features together in the next few months, and can start pushing towards something with RStudio-levels of polish around the new year.
Of course, the more contributors we have, the more this process speeds up, so anyone who wants to help is more than welcome to reach out :)