This way, many people think to rationalize their irrational beliefs. Also, it makes their religion sound super sophisticated: "science 'only' explains the 'how', but religion knows the 'why'!"
Of course, the claim that "we can't bring any contradictions between science and religion" just shows how scared people really are to subject their beliefs to proper investigation.
But it turns out that...their claim is simply untrue. Judaism does indeed occupy itself with a whole lot of 'hows'. Some examples where the Torah tries to explain the 'how':
- How the world was created (not why)
- How man was created (not why)
- How the Mishkan was built (not why)
- How the Jewish people were redeemed from slavery in all its details (the why not being the focus of the story)
- How the Jews traveled through the desert, where they stopped, etc. (the why not being the focus of the story)
- How the Torah was given in all its boring details (not why)
- How sacrifices are to be brought in all its boring details (not why)
- Etc., etc.