Happens in textbooks, too. Even math textbooks. It's not hard to tell who has decided to write a textbook and who is on the forefront of math research. They aren't the same people. Those who write textbooks often come close to outright copying of examples and methods letter for letter. That, plus the mass of typos and poor grammar is either on the increase or we're just getting more aware of it.
There is a lot of sloppy science out there in the world of research, lots of cheating such as manipulation of data, and stealing of ideas from others goes on.
Have you heard of Conway, who wrote standard texts on analysis, real and complex? (Another well-known author is Lang, with a series of texts used in many universities).
Or Halmos, whose measure theory book was a standard undergraduate text and is still recommended in most schools?
Or Arnold, whose book on differential equations is standard? Or Massey on Algebraic topology?
In physics, similarly, Dirac's book on quantum mechanics and Landau-Lifschitz series are still standard. Go check the contributions of these authors before you start saying such nonsense.
Not only is you statment is not based on fact, but you base is on a completely wrong premise, suggesting that inventors of ideas should be the ones writing the textbooks. They do not: these two activities requuire different talants.
Now, which of the above mentioned textbooks have you actually read?