While it is possible to do, there is an important cost benefit analysis to make. All of the benefits the article lists can be a drawback as well. Say your specific network needs tweaking to get good performance, with a unikernel you must do this with all applications, while for a "traditional" monokernel you can do it once and it works for all applications.

That is not to say the approach is not interesting, but it'll probably be for in some kind virtualization, where you abstract away the OS entirely, and run applications directly on the hypervisor.