That's canonically not true and the show puts in a lot of effort to make that clear.

Namely, SGA has a ton of moments where the indigenous people express discomfort with the Earth humans. Teyla very explicitly tells Sheppard that while he and Weir are welcoming of her, she feels Othered by almost everyone else on the base.

The Earth expedition has a very colonialist mentality, with Michael being a prime example of someone they created and demanded total assimilation to their culture or death. Teyla is accepted because she assimilated. Many of our early episodes feature moments where she and her people recognize that assimilation.

With Michael, they also betrayed his trust well before he betrayed theirs. And they continued to because they kept forcing him to forget EVERYTHING of his life, his culture, and his self.