I would at least like to understand the idea of 'pureness' this API tries to aspire to.

It's definitely not Unix-like, since file handles and writes and epoll, and mmap for IPC are nowhere to be found. Instead you have 'objects' with these lifecycle methods that create/release resources (probably committing the design sin of having these for things which should be pure data, like descriptors).

What's with these XML headers? It's UNIX standard stuff, to have a C API for your code, that declares an API for a library, and then a makefile can just consume it. There's a standard way of supplying, finding and consuming them. Even binding generators are probably more comfortable with C headers, than this XML thing

And what's with the callbacks for everything, like screen resolution queries? In Win32, you can do it with a single synchronous API call that returns a struct that has all the info. It's not like you have to touch the disk or network to get this. In cases where you do, you usually have a call that dispatches a message to another window (which you can also dispatch yourself), and you have to listen to the response.

I did some X11 programming as part of work, and its entirely reasonable and conventional compared to this, much more like Win32 (even maybe a bit more pleasant, but I'm no expert on it).

The API sounds awful (and I've had ChatGPT generate me some example programs, and it's somehow even worse than the author describes), and not only that, the requirement of 'everything be an object', with chains and trees of objects being created introduces a huge source of bugs and bookeeping performance overhead on the application side.

Yes, you do have to do something like this with some things under Windows, but the reason for this is that these objects have duplicates in the Windows kernel.

But here it looks like this is just to satisfy the sensibilities of the designer.

Honestly this sounds like the most epic case of NIH syndrome. Like these guys wanted to write their own OS and userland and break with existing conventions.