I think people simply favour tools that integrate well with each other, but if you develop 10 small swing tools it’s unlikely you’d be able to get them conveniently integrated into an editor.
That being said - I can certainly envision some richer GUI REPL state inspection tool. E.g. on top of Orchard you can easily implement a ton of such functionality in a trivial manner.
@bozhidar there's a lot I want in my editor too tbh. Inspector / state inspection seems good for swing though.