The reason for this is simple; where does the right of self-determination end?
Every right ends where similar right of another person starts. Or in case if they are contradictory - then majority decides. This is why referendum or a plebiscite should be carried out and areas with majority voting for independent Catalonia should be allowed to split from Spain.
I have argued before that human beings don't have the 'right' to anything.
I have learned something different during Theory and Philosophy of Law lectures, but OK - you are entitled to your opinion as well.
It is basically hypocritical woo-woo bs.
Not to any greater extent than a state, for example, is. A state, a government - these are too just artificial, hypocritical woo-woo bs.
If you want to think like this, of course.
Self-determination is a farce,
Not more a farce than National-unity or a state or any other political organization in itself.
Basically everything is a farce apart from physically touchable objects, right? If you want to think like this, of course.
The very problem is, that most people just don't think that way. It's a major flaw of mankind
If you don't think like majority of mankind then you are flawed - not mankind.
Because what is the standard? The standard is determined by majority. You are non-standard, out of line - not mankind.
What is the easiest solution to solve this "problem"? To change entire mankind? Or to change just you, who are out of line?
we are prone to think in terms of tribes in general. We are tribalistic creatures.
Yes - humans are gregarious animals, not reclusive animals. You have just stated the obvious. Everyone knows this.
It is not a flaw of mankind - if humans were reclusive animals, they would have never created anything like language, civilization or technology.
We would still be hunter-gatherers wandering around the savanna in Africa, each of us alone (apart from mating seasons).
So your individualistic approach to mankind is simply against the very human nature, because humans are tribalistic creatures...
And I see no reason to consider this as a major flaw of mankind. As I wrote - without tribalistic nature, we would not achieve anything. Without tribalistic nature the road of mankind from small family groups consisting of few people (in such groups for example Neanderthal people lived) to complex social and political organizations numbering millions and exercising power over some territory, would be impossible.
You could say that self-determination and basing states solely on ethnic boundaries is crap
Self-determination has nothing to do with ethnic boundaries because there can be a community consisting of various ethnic group who still feel common interests and want to self-determinate themselves as one state, with many ethnic groups included within its political borders.
Self-determination of population of some territory can take place regardless of ethnicity, without paying attention for ethnic composition, but basing on other factors - people of some territory can share various kinds of common interests, views, ties of various kinds (not just ethnic ties), etc.
One example of such self-determination which was not based on ethnic factor, was self-determination attempt of the CSA - inhabitants of the CSA were of various ethnic groups, because they (and their ancestors) came to America from various European countries (just like in the North).
What if the Turkish minority in Germany decides that they don't want to be German anymore and create their own state? Or become part of Turkey? Is that okay?
Turkish minority in Germany is so dispersed and divided that in no single place / area of Germany they are majority of population. Moreover - they emigrated to Germany for other reasons than to create their own state there. It was economic emigration - "in pursuit for bread". They do not form one political community. They do not share any political or economic interests so far. They do not have common goals to achieve, they are not well-organized so far.
And majority decides. You need majority of population of some territory to decide about political fate of this territory.
Opinion of majority is integral element of the right to self-determination. The right to self-determination does not allow minority to decide for others.
But similar thing to what you described still took place in real history - just replace Germany with Palestine and Turkish minority with Jewish minority.
However, in Palestine Jews - even though they were minority - had strong economic position before Israel was founded. They owned majority of all land, even though they were only 10% of inhabitants. Majority of Arabs (who now call themselves Palestinians) worked for their Jewish employers.
Who knows - maybe after 200 or 300 years from now, Turkish minority in Germany will be majority (at least in some part of Germany) or will have strong economic position and they will consider themselves as "oppressed" and thus will want to establish their own state in Germany. But this is far future.