There are several things contributing to over-abstraction. Two that I can think of:

1) Professional programmers are constantly hammered with the idea that abstraction and decoupling are always desirable - you've probably heard about TDD. Somehow OOD has been taken over by this school of thought and there are very few good resources on what good OOD is and looks like.

2). Dynamic OO languages force one to have high coverage and many tests to make up for the lack of static verification.

And I don't agree with the TLDR, over-abstraction is not a disease that affects only OO languages.