They mostly think their opinion is the right one, and others are just flailing around not understanding the real "objective" "truth". But they never spent more than a minute thinking things through and re-evaluating their biases and "objective reality"...
They then spend quite some time ranting about things that are obviously political, but on the same breath say they are proud not to vote...
I am a hacker, a baker of breads, a father, a debater, a thinker. Period. Not libertarian or whatever. My ideas sometimes are more like a democrat, sometimes more republican. I often like Bernie Sanders, and Schwarzenegger would be a nice, good, kind republican president imho. I don't like being seen as a part of any of these groups. I enjoy discussing reasons for "the 2 party" (but not really 2 party-) system much more than discussing which is morally superior.
This, to me, is a valid stance. For some it is the way to stay sane.
To deny another human being the rights you enjoy is imho the same as denying yourself those rights (because I, as a 3rd person, see both people as equal, and otherwise there is a paradox). This is the basis of our justice system, we "put people away" in cages, and in some places even kill them, because they believed their right to swing their fist does not end at someone else's nose. But presumably they would not enjoy a fist to the nose themselves.
But does it mean "100% open borders"? (notice the 100%) Should those rights pertain to (higher) animals? (notice the "higher")
There is nuance to explore, there are many ways to be a humanist. I.e., dumping mosquito nets in a mosquito rich area may be seen as helping, but not to local mosquito net makers (and thus you are not helping anyone in the long term, because the mosquito net makers are all bankrupt).
There is always nuance. And there are always exceptions, and your statements generalize exceptions to much larger groups, demanding action on a scale that is unwarranted, imho. Both sides are responding vividly to exceptions, to lack of nuance, to 160 character statements in all caps.
This strategy works poorly to avoid conflict and friction (life), since one just shifts conflict to reappear elsewhere. Hence the often claimed need to self-isolate "for mental health" to avoid getting in contact with... positions such as one's own, and half-suppressed anger at all those that just don't see what is RIGHT.
Hint: It doesn't work.