Because then your actions will not lead to more peace and just complicate things further.

Territorial integrity is often at odds with self-determination. In the case of Georgia and Ukraine the west argued with sacred territorial integrity - and in the case of Kosovo with self-determination. And russia argued reverse.

I have not been in all those areas, so I don't want to judge, but I do know that there was lots and lots of propaganda going on and allmost nobody really asked the actual people living there, what they actually want - which is what I prefer to apply in most conflicts. But this not so easy either, because ... does the vote of a person living there since only 2 years count the same as one whose family has been there since centuries? Where to draw the line?

Otherwise it gets ridiculed when for example occupying russian soldiers in chechenya gets the same vote as the people who actually lived there.