Why do you expect someone who hasn't yet become a citizen to say otherwise? My sister assimilated, got used to the idea that she would settle in the US and live like an American, then her green card application got rejected (something about repeated errors by either her employer or attorney). 2 years later, she's still gradually recovering from the mental health impact and rebuilding her life elsewhere.

You can't both have a system that can kick people out on a whim with zero recourse AND expect those people to be fully devoted to being American before they actually become citizens. They have to avoid committing fully before them, and especially nowadays with the unnecessary cruelties of the current administration (the entire "fly back within 24 hours or pay a fee that we don't yet have a process for" thing)