> Don't worry, we share similar views.
No, we clearly do not. If you held similar views to mine, you would not have posed the question, nor followed it with a false dilemma between breaking down regional identities and, "everything sucks. And there is no cohesion between peoples."
> And yet, I went through public schooling, learned the "national" identity but I still retained my own unique identity and cultural practices taught at home by parents.
To the extent that an American national identity exists, it is rooted in shared ideals and beliefs. Those ideals predate the system of public schooling devised by Prussian officer-aristocrats in the mid nineteenth century. Our ideals have certainly taken a beating under that system. Hopefully, they will also postdate it.
Given that you believe you learned the American national identity in a public school, I do wonder a bit about how well you understand that identity. Especially in light of your initial question, which implies a lack of understanding of why Americans might oppose a major institution.