Do we need to let every kind of complete insanity run its course and generate a body count?
The book did (as I recall) describe Hitlers plans in some detail, so had more people read it, maybe they would have done something.
Anyway my argument was sorta the opposite: the book did manifestly not sell well enough that it became how most people got converted to Nazism, and if more people had read the book they might have realized that Hitler was doing exactly what he wrote in his book and stopped him at an earlier point.
"""To make the list, it is estimated that novels sell from 1,000 to 10,000 copies per week, depending on competition. Median sales fluctuate between 4,000 and 8,000 in fiction, and 2,000–6,000 in nonfiction. The majority of New York Times bestselling books sell from 10,000 to 100,000 copies in their first year.""" - https://en.wikipedia.org/wiki/The_New_York_Times_Best_Seller...
They controlled who was allowed to express themselves and how. They limited everything to their message, even suppressing branches of science that didn't support their views.
That we as a liberal society can tolerate illiberal views is important. You should read things like Mein Kampf and the Unabombers manifesto - not because they are good but because you should know your enemy and how they think.
Strawmanning an argument is poor form.
Mein Kampf has existed and been available, and hasn't actually really caused any harm. That doesn't make it a better book but the hallmark of liberal society is that we can tolerate dissent while an authoritarian one can not.