But it isn't a single function definition it is the whole API. Deciding that you want to pitch your API at a specific level of abstraction and ensuring that lev

But it isn't a single function definition it is the whole API. Deciding that you want to pitch your API at a specific level of abstraction and ensuring that level is consistently maintained across a whole language is hard work. The recent criticisms of ASP.Net Core's API changes or PHP's "interesting" APIs over the years surely demonstrate that writing language APIs is hard.