It kind of is. I didn't say that Luffy just takes anyone he likes, I said he takes anyone he likes on a whim. Whims aren't complicated things, it's a momentary desire. If there is some logic that Luffy uses besides "I think this person would be cool to have on my crew" I don't see what it is.
I'm not saying writers shouldn't plan things out. Obviously. There is nothing in the post your quoting that remotely implies anything that. What I'm saying is he's set patterns for the crew joining that don't really have a diegetic reason to be there, atleast as far as Luffy's concerned.
Luffy doesn't take on people because they have big dreams of doing something or anything. He mostly just gives them the once over and decides if he wants them on or not. It'd be one thing if characters told Luffy these dreams and Luffy then decided to take them in on that basis, but he just takes them and they just happen to have dreams that require them traveling the sea.
Yeah, that's not the thing I was addressing though. I agree Luffy stating that he wants 10 crew members is a deigetic reason (even if it's a rather arbitrary one. Why 10 in particular?), but I'm talking about using "He likes soccer, therefore 11 members"
Like, no one else ever does this. No one thinks "Oh, Brandon Sanderson had likes Overwatch, therefore it's reasonable to say his characters are going to meet a ninja character like Genji" or anything. I'm not going to say a blanket statement like all, but the vast majority of theories base their suppositions on the things that happen in the story to predict the things that will happen. And yeah, the theory has some of that going on, but that it's using Oda's habits as a reason for something in story happening brings attention to that it's Oda writing the story.
For me, the basic problem is this: If we were to think of who else is joining based on how Luffy makes his decisions, we don't really have much to go on. Luffy just has to like someone. It doesn't mean they will be picked, just that he happens to like them. To make any kind of meaningful speculation, we have to move back and consider other things, sometimes things that Luffy doesn't even know about today (like the crew's tragic backstories we are shown in flashbacks that are never verbalized). We see if we get a sad flashback chapter of them, or they need to have a dream to leave the island they're on or whatever. None of these are reasons that Luffy invites them, but it's the pattern set, just because Goda made it so.
It's a question that requires me to stop thinking about why Luffy does what he does as a person and just think of the story's tendencies instead. And if you go beyond that and decide that Oda makes his decisions on whatever random thing he happens to take interest in, then that's not even thinking about the story at all. It's just trying to speculate about what Oda does.
That's why I said I don't see how that kind of speculation doesn't take you out of the story. You literally have to think of One Piece as an artificial product, rather than being immersed in the world itself. And it's fine to disagree with me on this, I'm just saying it drives me up the wall. I like to have as few reasons to think of the story as an artificial product as possible.
