I'm sorry, but he is right. Adjoints are everywhere [1]. Referencing adjoints is indeed pretty vague. You can't make a case for why things are interesting by q

I'm sorry, but he is right. Adjoints are everywhere [1]. Referencing adjoints is indeed pretty vague. You can't make a case for why things are interesting by quoting a bunch of resources of other people making cases why things are interesting. (I guess you can, but then, why make the argument at all if it is not yours?) You don't even need funny names to get x^2=0. This is true for any of the two elements of the group of order 2. Linear logic is indeed having a mini revival, but so is general category theory. I don't see the particular advantage for people to evangelise certain parts of mathematics, especially if the case being made is not clear. [1] Not attributed to me.