It's perfectly reasonable for nation states to challenge the EU institutions, because the 'legitimacy' of EU institutions is not arbitrary - it depends on the s

It's perfectly reasonable for nation states to challenge the EU institutions, because the 'legitimacy' of EU institutions is not arbitrary - it depends on the support of member states! If an EU institution is challenged by most members - it should absolutely be 'de-legitimized' and closed down! This is the problem with the pro-Federalist psychology - added to the reality of 'bureaucracies that can only grow' - we 'assume' that a given EU entity should have supremacy, and not be 'undermined'? Why not? Who gave that EU organ power in the first place, and why does it have it? I don't really support Lux's attempts to continue their low-tax status, but maybe they have a point. As far as the Lux language - I think your argument is a stretch. Surely you know there are a zillion languages in the EU, each close to some other language. Having Luxembourgish 'recognized' doesn't necessarily carry them any favour or economic advantage, so I don't see how it's super relevant. I see what you are trying to get at - I just don't think that specific case is a good example.