I think SyrianGirl and the Syrian soldier she interviews place too much emphasis on nationalism and the sanctity of the state concept by attacking the federalism that is advocated by Syrian Kurds. On the other hand, the Empire and its allies like to use religious sectarianism to break up states to make them weaker and more easily dominated. Michael Jansen also sees federalism as simply a ploy backed by the Empire to divide and conquer regions of the world.
History reveals that states have been created on the ruins of the old feudal system when kingdoms were established through violence after the Roman Empire disintegrated. The capitalist class took over control of these regions which were integrated into states that we see today. Imperialist capitalists have also used the divide and conquer strategy in many parts of the world to establish new states, particularly in the Middle East, to break up nations that posed threats to their control or to their access to resources. Thus states can be regarded as a creation of the capitalist class. It is interesting that now under neoliberalism that the US-led Empire is trying to reduce the power of all states in favor of the transnational rule of the Empire.
I think there is another position of federalization that can be argued as a progressive development: the breakup of states on the basis of natural bio-regions. Also there are various degrees of federation that can be used to decentralize power and to promote more grassroots participation in decision-making which is what the Syrian Kurds have been thinking based on the influence by progressive thinkers like the American Murray Bookchin and Kurdish Abdullah Öcalan and the concepts related to Libertarian Municipalism (see this, this, and this). SyrianGirl, Jansen, and others simply don't understand some of the progressive ideas of the Syrian Kurds. But it may also be true that the Kurds don't understand that they are being deliberately led by US agents down the path of national independence for a Kurdish state which would facilitate the breakup of Syria, the Empire's "Plan B".
On the other hand, I think it is a bit dangerous to experiment with such ideas of decentralization while the Empire goes about breaking up states for their purposes of world domination. It is the Empire, and particularly the US that needs broken up, and this likely should be accomplished first before other states do it.
I perused a Kurdish website this morning and found more evidence that the US is supporting and courting the Kurdish desire for greater independence. The fact that this article was re-posted to a Kurdish website suggests some naivete among the Kurds. To agents of the US Empire this, of course, means balkanization of Syria . And I just found a post that indicates that the Syrian Kurds have declared themselves to be a "federation". But the details of what they mean by federation are missing.