How do you know those scholars aren't also pretending?

Because your theory suggests that "real Judaism" was built on the foundation of "fake Judaism" because the Jewish Talmud has existed since the first days of Judaism, long before it was transcribed into books when it was passed down verbally from one generation to the next. Respected Jewish scholars have contributed to the Jewish Talmud since the very first days of Judaism.

Such a theory tumbles away into the realm of semantics and becomes as meaningless as arguing that apples should be named oranges and oranges should be named apples.

Why do you believe the buck stops there

Because nobody has provided a more articulate label for the Khazarian Jews.

The best scapegoat most people can come up with are more ambiguous terms like "bad people" which is like arguing an autopsy report naming the cause of death as "arsenic poisoning" is wrong because arsenic is a thing so the cause of death was "because of a thing".

Yes, they are all bad people, but it's more accurate to recognize they are all Khazarian Jews... because they are. It's that simple.