python comes with IDLE. Which looks dated w.r.t current IDEs. I guess for most languages, stability is the key - changing UI also means maintaining two different UIs(the old and the new)- that time could probably be better spent on language features.
DrRacket is a bigger deal to Racket than IDLE is to Python. Specifically because it provides a graphics capable REPL, which is used by a lot of the pedagogical languages and intro to programming courses that racket is perhaps best known for.
> changing UI also means maintaining two different UIs(the old and the new)-
Why would you need to maintain the old UI? Backwards compatibility isn't an issue, since no one is screenscraping and doing image recognition to interact with the UI.
Besides, what we're discussing are relatively minor changes to update appearance, such as different font, color scheme, graphics assets, etc. No significant changes wrt UX--with how the user interacts with the program.
For more extensive changes, I imagine a whole load of screenshot-heavy documentation would need updating (probably a load of course notes, inherited from long-gone lecturers too).
I agree that shouldn't be an issue though. Those who don't want any change (e.g. lecturers) can stick with an old version.
