Unfortunately it’s pretty common, and I for the life of me can’t trace out why.
The rest of Georgia resents Atlanta, NY state has unease about NY city, Pennsylvania outside the two big cities has lots of disharmony with the big two, Oregonians hate Portland, and so forth. I guess the feeling is “this one place has too much influence”
It’s mainly because of political and cultural factors unfortunately. I grew up in Louisiana and have visited NY state multiple times and noticed that both states have the same level of disdain for their largest cities.