I think Tk is entirely reasonable for the types of "utility" applications that people are primarily using it for; nobody is going to start writing a flashy new

I think Tk is entirely reasonable for the types of "utility" applications that people are primarily using it for; nobody is going to start writing a flashy new cutting edge app in it today. For those with legacy code or other constraints where it makes sense, the TkDocs site is all about getting the most out of Tk by documenting the newer pieces that people likely haven't seen. IDLE itself is in that category of using Tk by constraint. There have been multiple forks of it, sometimes using alternate GUI toolkits. But for it to stay as part of the Python standard library, it has to only depend on other things that are part of the standard library. Which for GUI stuff, means Tkinter. And having it built into Python is a very big deal for a lot of people teaching Python, which is the main target audience.