[Fishkins]

This is a survey conducted by JetBrains, whose primary product is a Java/Kotlin IDE. They do support other languages, but their audience is almost certainly skewed toward JVM users.

[dijit]

Additional: Some languages really do lean on IDEs. Java and C# are prime among those languages.

Writing Java or C# without an IDE is painful.

Writing Python or C without and IDE simply lacks creature comforts.

So any demographics used for a survey of an IDE company will skew for "IDE focused" languages. All else being equal.