No I meant how can that mindset survive past first contact.
Our first encounter was a ****ing war.
Kind of how Americans could have communist sympathies during the Cold War or how UC-Irvine Students could label the American flag as a symbol of racisim, nationalism and imperialism(Just a real world example for Warder. Not looking to debate that non-Dragon Age topic). Regardless of where they were born, some people will choose to think that the society they grew up in is bad and therefor should be rejected in favor of some sort of alternative, be it another nation or none/all nations. In less extreme cases, they simply argue for great reform. In Mass Effect, you've got Garrus, who seems to favor a human point of view, or at least doesn't toe the turian line of thinking or Kaidan who definitely equates human interests to those of non-humans through use of a unified cause. Neither of them are in any way AGAINST their people, however. They both feel a great deal of loss for their homeworlds and clearly want to end their respective sieges.
Another POV is that some people favor what is best for the most amount of people, regardless of the 'tribal groups' that have been formed up to that point. They favor a unified voice rather than promote the interests of their birth 'tribe'. The Inquisition is actually a very good example of this. And Cassandra is an excellent example of a person who holds this point of view without rejecting where she has come from. She still favors the Chantry, but knows that the Chantry's interests are not important right now. She knows that the cause is bigger than her 'tribe'.
Don't get to thinking that I am against being proud of one's nation or heritage, or even aggainst nationalism as a rule. Just pointing out how both humans and non-humans can rationalize not being strictly pro-whatever their race/nationality is.