We are a different country from Russia and therefore have a different way of life. Sometimes what is "normal" and "modest" also depends upon the area and weather. How one dresses in a parish vs a cathedral might be different. How one dresses in Seattle vs Miami may also be different.
I don't think women in America not wearing headscarves is necessarily an anti-Church conspiracy. Yes, we may prefer women cover their heads, but we don't force it here. I'd rather women wear a headscarf because they want to and not because it is mandated or else we'll start start turning into the religious police in Saudi Arabia; where an all-girl school was left locked in the school to die because they all left their hijabs inside.
I've seen men and women both in Miami wearing short-sleeved shirts and slacks to church and sometimes with or without headscarves. It is very hot and humid in Miami and anyone who wears a three-piece suit is a glutton for punishment. At my old parish in Washington state, wearing jeans and a sweater was the norm because it was a poorer area and very cold. No one had a suit there. The "fanciest" dressed people were the priest and deacon. Most OCA parishes I've been two (on both US coasts) have had a mix of women with and without headscarves.
The three ethnic Arab parishes I've been to (California and Maryland) I think had the right idea. They did not mandate wearing a headscarf unless you were going to receive Communion. Wearing one before or after was optional, and they even had a basket of extras to borrow.
And, if I may be so blunt, I think if you are allowing what other people wear to church bother you so much, then perhaps one needs to reevaluate one's priorities because there are a lot more important things to worry about in life. Metropolitan Anthony of Sourozh once gave a homily that went like this, "Yesterday, there was a woman and her child that came to church. She was not Orthodox. She did not have a headscarf. She was chased out of the church and will likely never come back again. Whoever chased her out, her salvation is now on your soul. Do not chase people out if they don't have a headscarf."