This is an example of a coherent joke, though apparently I had misunderstood it. I thought Robin didn't want to do docking because she is a more solemn personality than the rest of the straw hats and considered those shenanigans to be beneath her dignity. That is a joke that makes sense why it would happen. I'm disappointed if the punchline of it was "lol women" rather than "lol Robin"
The first Docking joke was used based on Robin´s personality, sure. We can all agree on that. The following robot jokes was just a deviation of this first joke, it works more like a callback and also as a joke on its own, because whenever a robot is showed men get EXTREMELY excited, meanwhile girls are showed not excited at all.
So here is another reason why: Its called a comedy duo, that is a staple in Japanese comedy, you have the funny man and the straight man. The funny man is the one doing wacky stuff and the straight man is the one calling out him on them, acting outraged. This is fairly common in other cultures too, but in Japan its used a lot more. The reaction of the straight man makes the actions of the funny man, well, more funny, because now you can laugh both at the joke AND at the reaction of the joke.
In One Piece, this role was given originally to Nami and sometimes to Usopp, whenever another strawhat did something funny they would be there to provide a snap remark about how wrong is for them to be so wacky. Later on we got introduced to Robin, who is usually not a straight man, but given that she is the most serious of all the characters her reactions are also funny when she does show them, precisely because is so unusual of her.
Now, back to the robot joke, the reaction of the boys for robots is made more funny because of the lack of reactions by the girls. because of simple contrast rules. As a reader we will think the following:
1)Why do men find robots so awesome? Robots are cool but their reactions is too much, that is a funny face they are making.
2)Oh wow, why are the girls finding robots NOT awesome at all? That makes no sense, robots are cool, but their indifferent faces are funny too.
Both are exaggerated reactions, it is of note that Luffy, Chopper and Usopp are usually the ones that lose their shit when they see robots, while the other males are shown happy or slightly excited about it.
And as Worldbuilding it makes sense too: Nami went from calling out everything, to acting all frustrated because she can´t keep the boys for acting like idiots, and, finally, to just put a face of total indifference. Robin has mostly always been indiferent that way, with some complacent laughs in between.