It's not about buying into nationalism, it's about buying into reality. This is the world we live in.
When anyone preaching anarchism or "true freedom" can give me an example of a group of peoples that were able to survive as a civilized society without some form or hierarchy (which is all government is, and is found in every natural ecosystem in existence) then I'll buy into your Utopian bullshit. Until then, have fun living in you're delusional world.
Again, we don't live in the world we want, we live in the world we have. And the only way to change the status quo is through a violent and bloody revolution, something that I'd be willing to bet my life on that most of the people preaching against the "state" don't have to stomach to actually do.
Until you've you've looked a man in the eyes and shot them dead don't try to preach to me how much better anarchy or a non-statist government is, because it isn't a pleasurable experience no matter how much your movies or video games may teach you otherwise.
Until you've done that you have no fucking idea what you're talking about. And the only way Utopia happens is through that, and then what happens after that? Oh yeah, someone wants more power than their neighbor because that is how nature works, but what the fuck do I know as compared to the brilliant minds here.