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.
IDEs made by JetBrains are huge. At this point, they're basically the standard option for several JVM languages.
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.