Well yes, but also no. You can’t reproduce a book because that violates copyrights.
Open source in this context just means that nobody owns the book, you can reproduce it however many times you want, and distribute it where you want as long as you include the original license in the reproduction (MIT license).
Also, there’s a bit of a colloquial understanding that others are able to contribute or fork the original source material.
But “open source” doesn’t even mean that you can reproduce it or use it for free. It just means that you can see the source code. The permissiveness, as you mentioned, lies in the licensing.
So I still think that it’s a complete misnomer.
Well yes, but also no. You can’t reproduce a book because that violates copyrights.
Open source in this context just means that nobody owns the book, you can reproduce it however many times you want, and distribute it where you want as long as you include the original license in the reproduction (MIT license).
Also, there’s a bit of a colloquial understanding that others are able to contribute or fork the original source material.
But “open source” doesn’t even mean that you can reproduce it or use it for free. It just means that you can see the source code. The permissiveness, as you mentioned, lies in the licensing.
So I still think that it’s a complete misnomer.
“Open source” and “source available” are different things. See e.g. https://opensource.org/osd and https://opensource.com/article/18/2/coining-term-open-source-software