first, you don't import "user.options", but rather the module: "mediawiki.user", which, in turn, makes the *object* mw.user.options available to you.
second, because these resources are pulled from the web, it is usually not such a great idea to serialize it the way you suggest. in principle it *is* possible to do it the way you outlined (one would have to write a "synchronized import" function, which is totally possible), but it would mean that the browser will "freeze", and do nothing else (it might be responsive to user input, but it won't be able to execute any other JS stuff) while the browser goes and pulls the module off the server, however long that takes.
in the current mode (using the "using" method), the browser sends a request to the server to pull the module "mediawiki.user", and while the server prepares and sends the module, the browser is free to go and play elsewhere and do other stuff, such as figuring out what *else* is needed, and ask for it. once the module arrives from the server, the "using" triggers execution of the inside function.