Closed source IDEs are if anything the norm: Visual Studio, Android Studio, XCode, IntelliJ, CLion, PyCharm, etc... Even in the "fancy text editor" category things like Sublime were always popular enough.
IntelliJ: https://github.com/JetBrains/intellij-community
PyCharm: https://github.com/JetBrains/intellij-community/tree/master/...
Android Studio: https://android.googlesource.com/platform/tools/adt/idea/+/r...
Yes, they might offer extended proprietary editions/plugins in addition, but the IDEs themselves are open source.
I've filed bugs with JetBrains before and had them take months getting to my ticket, often with multiple hand-offs between team members; being able to provide a potential fix should make the process much faster.
IDEs made by JetBrains are huge. At this point, they're basically the standard option for several JVM languages.