Most Helpful Guy
Two words: radical feminism link (which is different from mainstream feminism).
Militant radical feminists, particularly in the late 70s through early 90s, loudly denounced men for being chivalrous because they said it belittled women and made them seem like inferior beings who couldn't take care of themselves. They trained women to believe that if a man held a door open for them, that was offensive and demeaning to women, and so were other acts of chivalry, such as giving up a seat on mass transit. link
After several decades of this (and I've personally been attacked by militant feminists a couple of times for holding doors open, which I do for EVERYONE), most men just gave up and didn't bother anymore. If it's not appreciated, people aren't going to do it, and if you're verbally assaulted for doing it, you're REALLY not going to be motivated to be selfless.
But many countries around the world never had a Feminist Movement, so they never had radical, militant feminists teaching people this crap, and so some forms of chivalry live on. In Western countries, it's mostly gone, thanks to a small but loud group of women.