“Wouldn’t it be boring if we were all the same?”
That idea has been used as a defence of diversity and the right to be different. I suppose it’s okay as such. What I want to comment on — briefly — is a different use.
This is another place for the “I don’t know how common this is but I’ve heard it said” disclaimer. So, yes, that. This other way I’ve heard this idea used sometimes is about things like how men and women are “different”. Two (or more) groups are different, and it’s good because it would be boring if everyone was the same.
It’s just that you’re not talking about diversity when you say that. What you’re defending is a generalisation. Two groups can only be different if people within one group are somehow the same — not different from each other. If everyone was different, you couldn’t say it’s two groups of people specifically that are different. So basically you’re saying that every person being the same would be boring but just two different homogenous groups is the right amount of diversity. (Well, it’s just enough for Othering.)
There are all kinds of complications such as about legitimate generalisations and the fact that this kind of use of the “wouldn’t it be boring?” at first sight should include using it to defend cultural diversity (which I’m not talking about here) since that also involves groups. I’m not going into all that here.
Here, I want to make just one point: Sometimes when people talk about differences, they’re really talking about people being the same. If you’re defending the notion that there are two or more groups that are different from each other and therefore internally somehow alike, you’re not defending the idea that people are different — those who disagree with you will mostly be saying that people are more different than you are saying. Having just two or a few groups isn’t un-boring, it’s a false security. Having to take everyone individually, now that’s an interesting challenge. Thinking of two groups is just hiding from that.