I'm not running or playing 4E. If I were running it, my preference would be that, supposing WOTC decides to do anime-style content, that they keep it in one or more self-contained books. They can do "Heroes of Underage Schoolgirl and Pink Mecha" if they want. They can do a whole series if they want. But I really wouldn't want to see the content sprinkled in among other, unrelated content... since that would make it harder to excise. Or, if it must be interspersed, attach a keyword to it so that the DM can just say "The 'chibi' powersource may not be used in this game" or whatever. At least that.
That's what "ki" seems to be. A clearly attached keyword.
If I'm a player and I have signed on for one thing, I don't want the whole deal to get switched around on me just to accomodate one person's taste ("I *only* play motorcycle ninja cyborgs, regardless of the game system!").
No one is saying that. I don't have a problem with "this is a Tolkienesque campaign, that doesn't fit," or "this campaign has been running for a while, and never had dragonborn or kung fu before now, so kung fu dragonborn shouldn't be added." Those are entirely separate questions, because they deal with how an objective concern (the pre existing, objective tropes of the game) should interact with a subjective concern (a player's desire to play something that others feel doesn't fit the pre existing, objective gameworld). What I'm talking about is subjective versus subjective- I want to play a Kung Fu Dragonborn Monk, you want me not to do so.
Also, motorcycle ninja cyborgs? What would your thoughts be on a much simpler, actually-has-a-chance-in-heck-of-happening character class: Imagine a character that doesn't wear armor but does dodge well, tends to wield heavy blades, and who has a simple mechanic by which they "focus their ki" by spending a standard action on a weak attack so that they gain special bonuses when they "expend their ki" making a better, powerful attack. That's just an idea, and you may not like it, but that's the sort of anime trope you're likely to see. Cyborg motorcycle ninjas it ain't, so maybe they shouldn't be included in the discussion.
It's not irrational to ban anime, dragonborn, gunpowder (see, I threw in one that *I* like), spelljamming, etc. from the table. It's not irrational because it's a matter of taste... and I don't want any chocolate sauce on my steak, thanks. That's no dig against chocolate sauce, they just don't go together.
It depends why you're doing it. And its not really about rational versus irrational. Its about fairly weighting your preferences and interests against those of your friends. More below.
You talk of compromise. Suppose we're all sharing chips and salsa at a restaurant before our meal. You attempt to add mayonaise to the salsa. Everyone else gets on your case. Have you been unfairly maligned? No. You tried to do something that you like but would ruin it for everybody else. So you have to lay off the mayo or go get your own bowl of salse (game).
This is why I used the food allergy comment. Look. The better analogy would be that we all share a bowl of chips, but we each have our own bowl of salsa, and that while we may have to smell each other's bowl of salsa, and see each other's bowl of salsa, we do not actually have to eat it. The chips are the game. The bowls of salsa are our characters. You do not have to play my character. My character does not determine the game itself. But you do have to interact with my character. So you have an interest in my character being compatible with your idea of what the game should be, but it is not an unlimited interest, and its probably automatically less of an interest than my own interest in my character. (Also this varies depending on whether you're a player or a GM, etc.)
That's why I find Generic Food Metaphors about anime very uncompelling. They rely on assertions like "You tried to do something that you like but would ruin it for everybody else." And they include assertions that an anime influenced character, if played at the gaming table by somebody else, would somehow ruin your fun.
And obviously its not right that someone join a game and ruin the fun for everyone else. So that sounds very compelling.
Because, I mean, you say that an anime character at your table would wreck your fun. But... I'm not actually obliged to believe you, am I? I mean, it seems impolite not to believe you, but if I were the DM and you were my player, and you told me that the mere presence of someone else's character was going to ruin your enjoyment of my game, I think I might be obligated to consider how likely that really was to be true?
Because there are other possibilities right? You might be exagerating: you might dislike the other person's character, but be perfectly capable of enjoying the game if you just relaxed a little. Or you might be flat out lying because you hope that, by asserting that you have an absolute inability to game happily beside an anime influenced character, you will be able to persuade me to cater to your preferences. Or you might just be kind of self centered, right? And you might feel that your feelings on someone else's character are somehow way more important than theirs.
Given that the question is a social one: a question of social graces and the degree to which we tolerate one another when we come together to enjoy the same game, wouldn't I have to at least consider the possibility that the person giving me the ultimatum is the one being unreasonable, rather than the person at whom the ultimatum is aimed?
There's an old joke.
Two boys find a cake. They can't agree on how to split it, so they take it to their father. One boy says, "I want the whole cake!" The other says, "we both found the cake, we should each get half."
The father replies, "you should compromise. Give him three quarters of the cake."
That's where this seems to go to me. Two people probably should compromise. But one of them is insisting that his position is so extreme that no compromise is possible.
I wouldn't want to force one of my friends to sit at a table where someone is playing a character who is so hatable that the character's mere presence wrecks the game for my friend. But if my friend told me that was happening,
I would be kind of surprised. Because that's an awfully unusual thing to happen, isn't it? For someone else's character to be so objectionable that other players can't even stand to game with them, not because of how the character's player is acting, or anything like that, but simply because of race or class choice? Maybe I'd think my friend was taking himself and his own preferences a little too seriously, and should just chill and have fun with his own character.