The counter-example to this is C#. Barely younger than Java (by 5 years), and starting its life as mostly a Java clone with a sprinkle of Delphi, it evolved muc

The counter-example to this is C#. Barely younger than Java (by 5 years), and starting its life as mostly a Java clone with a sprinkle of Delphi, it evolved much faster and made many changes which "make things look better" without breaking things. Source-level compatibility goes pretty much all the way back to 1.0, as well.