How are these suggestions not pragmatic? You don't have to use them, but if you need them they are there. From a security point of view I can see many of these being incredibly useful.
If it slows down Rust development it's not pragmatic. And if it creates a cultural schism between full commitment and pragmatic approaches, it's also trouble. Remember Scala?
No, that's not how it works. See for example async: I don't need it (and indeed hate working with it, because colored functions are incredibly unpleasant to work with). But a huge swath of libraries in the ecosystem are designed with the assumption that you will use it. If the language adds more features like the article is proposing, it will most likely balkanize the crate ecosystem even further. This stuff does affect people even if they never use the features in question.