Against literate programming
Some genuine reasons to avoid this literate programming nonsense altogether
It takes time. In addition to typing code, now you have to write stuff.
Writing is hard. Coding is hard too, but it's easier to stay employed as a bad coder than it is a bad writer.
Code blocks encourage spaghetti code. Being able to declare code out-of-order can quickly obfuscate program flow.
It can easily devolve into simple inline documentation. The world already has enough of that thankyouverymuch.
Collaboration is hard. I'm not saying it's impossible, but think about how hard it is to collaborate on normal writing. Now add programming and source control on top of all that. By and large, it has historicaly been an extremely solitary or oligarchical paradigm.