That’s actually the good question to ask. Which would be better without gender choice? And which fixed gender ones would benefit from not being fixed? I don’t think there’s many that have suffered from allowing gender choice since the player is the MC and is directing the story.
It’s difficult to keep an MC personality on track unless you’re playing a very specific, predefined type character where some of your character traits are already assumed. So lets say you wanted to write a story about Lara Croft (or Indiana Jones for that matter). Your using her background, her personality, responses etc. You’ve got a predefined character (which can sometimes be a down side as it can restrict what options you can give to players.) They’re not playing as themselves, they’re playing how they think Lara Croft would react.
That’s not a wrong way to do it, but in this situation, you’re telling a specific story- it has downsides and benefits. And it can be limiting which many readers don’t like because you’re telling them what they must do, instead of letting them choose. Lara Croft and Indiana Jones are two very different people, with two different personalities. But, if you look at the basic story between these two, it can be pretty similar, (Enter scary tomb probably full of reptiles, find artifacts, get out without dying). Gender isn’t the important aspect here. It’s how people react to it that gives most of the story, rather than a normal novel that goes in a straight line.
The same with others like Moby Dick/Mary Dick- with a little adjustment, there’s no reason why it couldn’t be a woman hunting down the white whale instead of a man. Sure, men were usually the ones on whaling boats traditionally, but if this particular one happened to have a woman on board, why would the story be so different unless you made a point to make it that way? (Ie had the crew trying to kick her off the ship at every turn because woman on a ship were bad luck or some silliness like that). If she’s been accepted as captain, (and there’s precedent, look at cases of female pirate captains etc) the story could be adjusted without a lot of difficulty I’d imagine.
The only other cases I can think of is where you have a very specific and defined world creation. (Like in your example if you really wanted to do Pride and Prejudice: The sequel, and really don’t want to flip the world like choice of romance) Or you’re going for ultra real historical, where gender makes a big difference and don’t want to write separate male/female tracks to deal with that.
But let’s face it most of the choice games here lean towards fantasy to one extent or another. It’s not a large jump to move gender roles around, or just let people play the accepted exception since after someones flinging spells around, or riding on dragons, that usually seems like kind of a small thing. Basically if it lets people relate to a character better, why not?
BTW: Didn’t we just have this conversation recently?