Politely, I feel like this is the issue with OCaml as a community. You gave a beautiful answer about programming language design and composition. But how does it feel to write the language? How can you print a user defined data type? From reading around, it seems like your options are: explicitly pass a print function for that specific type, use a third party library for printing, or (my "favorite") don't. Or how does it feel to write a function that takes a generic that can be printed, checked for equality, and read? Or to convert one type into another type?
And we're still talking about semantics here. How does it feel to use the language server? How does it feel to read the code? To build the language? Ultimately that's what users judge a language on. Yes, Rust in some ways has a worse form of abstraction. It is global, not fully generic and doesn't allow for overloading. But it creates a user experience that is nicer. It lets a user print something and compare two variables and do type conversions without having to scratch their head, read a forum post and import a library.
And we're still talking about semantics here. How does it feel to use the language server? How does it feel to read the code? To build the language? Ultimately that's what users judge a language on. Yes, Rust in some ways has a worse form of abstraction. It is global, not fully generic and doesn't allow for overloading. But it creates a user experience that is nicer. It lets a user print something and compare two variables and do type conversions without having to scratch their head, read a forum post and import a library.