Well, heck, when your OP is about chivalry and treating women with respect, people tend to assume you’re only talking about women.
Frankly, I think good manners are fine, it’s just that some of the old ways of expressing them are kind of pointless, especially if they’re only applied to women. Standing up when a woman enters or leaves? Why? What does that do for her on a practical level? If it’s a sign of respect, which historically it is, then it signifies respect regardless of gender. So do it for both men and women.
As for holding doors, it’s a nice gesture. I’ve never felt slighted by someone holding a door for me. And I return the favor on a basically daily basis, for both men and women. But there are some instances where it’s not appropriate; take** Ferret Herder**'s example, where a visitor to the hospital holding a door for her contraindicates her job guideline of letting patients and visitors off the elevator first. If “good manners” involve getting in someone else’s way, then it’s not “good manners.”
And I’ve never had a chair held out for me that I didn’t have to scoot and adjust anyway after sitting down. It doesn’t help and I wish people wouldn’t do it, traditional good manners or no.
And DON’T get me started on guys who insist on relieving me of anything remotely heavy that I’m carrying. I’ve got it, dammit, I know my own strength; if it looks too heavy, 1)ASK ME if I want help, 2)if I say no, DON’T TAKE IT AWAY FROM ME ANYWAY. This actually happens. You want to help, take my purse for a moment; it’s also heavy, and it dangles and gets in the way. Funny how no guy ever offers to take that off my hands.
I’ve asked men how to do things (run machinery, use a power tool, etc.) and sometimes the response is “Oh, I’ll get that for you.” NO, thank you, if you’ve got the time to do it, I’d rather you show me how to do it myself; someday you won’t be around to do that when it needs doing, and I won’t know how because you insisted on doing it for me. That’s not respect, that’s patronizing.
Basically, take a look at any activity that you think of as “good manners” or “doing a favor” and ask yourself two things: if you would do it for another man, and if you would feel weird or awkward if another man did it for YOU. If the answers are “yes” and “no,” then do it for women with a clear conscience. If those aren’t the answers, ask yourself why those aren’t the answers.