This is certainly not the case. Some, but by no means all, of the core maintainers prefer the unicode glyph, but the vast majority of the code uses a spelled-out lambda.

In my current checkout of the codebase, I see the following:

    ~/src/racket/racket/share/pkgs$ ag lambda **/*.rkt | wc -l
    1041

    ~/src/racket/racket/share/pkgs$ ag λ **/*.rkt | wc -l
    163

Note also consistent usage of spelled-out lambda in the Racket style guide, https://docs.racket-lang.org/style/.

I made a mistake, believing that `ag` could handle extended glob syntax. The real numbers are:

    ~/src/racket/racket/share/pkgs$ find . -iname '*.rkt' | xargs ag lambda | wc -l
    33589

    ~/src/racket/racket/share/pkgs$ find . -iname '*.rkt' | xargs ag λ | wc -l
    16722

Glyph λ is more common than I thought, but still heavily outnumbered by spelled-out lambda.

I am using lambda as I hate small symbols. I have to stop and process what λ is.