This generalisation is easy to explain. On the server-side, Java "won" the enterprise battle. In the last 20 years, big corporates re-wrote their server-side C/C++ stack in pure Java (and thick desktop clients in C#). It is so much easier to maintain than C/C++. As a result, they can hire mediocre Java developers to maintain their "new" legacy services.

    who produce mediocre code based on the wrong ideas of object oriented programming

This overlooks this history of OOP. Each decade, lots of new ideas have emerged so that skilled programmers continue to use the same languages (Java, C#, C++, C), but change how they use them. C++ in 1996? Let's fight about diamond inheritance! C++ in 2006? C++ in 2016? C++ in 2026? Repeat for all four languages that I mentioned. The story will look similar. Anyone good writing new code in these four languages isn't using many levels of inheritance. It is gone. Sure, it exists in the language for historical reasons, but it is hardly used in new code. "Prefer composition over inheritance."