Earlier quoted context omitted.
The greater region of Montreal considered separating from the rest of Quebec if Quebec were to have separated from Canada. Same with some Aboriginal communities (who in some ways control vast areas of land, greater in size that many European countries!) They were quickly denied the right to do so on a legal basis. It never came to fistycuffs, but it could possibly have. Independence movements are a tricky thing.
In any democracy or lawful state, independence movements are just a matter of nationalistic feelings. It's normal they are a tricky thing. They do not obey the principles of solidarity (in this case) or rational thinking. They live mainly from either supremacist or victimization arguments.
People are different, cultures are different, ethnicities are different.
Why do you think that after 1000 years of war (in the case of the 'Germanics' - you could say 2000 years, i.e. against the Romans) - that places like 'Germany' still exist as a relatively coherent entity? Even when they were not 'a single state' they were allied.
The boundaries of Europe for some reason always seem to 'snap back' to something resembling an ethnographic map.
Why did the Greeks - who were never 'a country' in antiquity rallied together in defence against the Persians?
Far from being 'radical' it's actually the epitome of 'reasonable' and even 'pragmatic' that ethnic groups want their own states.
Every case is different: Catalonia, Scotland, Quebec, former Yugoslav states, heck - even Crimea ... but there's always at least some reason behind these movements - even if it does get caught up in 'stupid nationalism' or even, sadly, 'stupid racism' - those are usually just the extreme voices. Most people are not like that.