People like JSON? A format that forces spurious quotes, making it hard to read, as well as lacks comments, making it hard to document. Or do they mean as a pure transport format? In which case... Who "likes" these kind of things? I might have strong feelings about endianness (LE just doesn't feel natural) or stupid bases like 10, but a mediocre serialization format?

And it doesn't surprise me that Haskell users dislike thing. Once you use a superior language, you really realize how much things suck. People warn about this in jest: don't learn <fp lang> because you'll hate working in other languages. But it's quite real and true. After being in a high level language with a good type system, working in a "mainstream" language is like trying to explain stuff to a subpar 6-yr-old. It's just incredibly frustrating.

(Working with one customer that chose C for their large codebase due to performance... Except the incredible verbosity ended up hiding terrible algorithms, and the lack of abstraction means changing things is a huge undertaking. Or on C# projects, every 5 lines of code I write I realise how it'd only be one in F#. Or how a long-standing bug would not have been possible due to more sane compiler checks.)