The I stands for Integrated. Although technically I think the big 3 Java IDEs are written as a pile of plugins largely to support multiple languages. But they do tend to feel more "integrated"/look more cohesive. I guess the point is that if you feel like opening a text file in something it's a text editor. If you don't it might be an idea. I do try to open up individual text files outside of a project in pycharm sometimes but usually it feels weird. Maybe that's why they added scratch files. Somehow shift+shift new scratch file json and copy/pasting feels easier then making a new file outside your project with the IDE