For the same reason omitting braces in C-style-syntax conditionals and loops is questionable, i.e. misleading indentation.
As a bit of an unreformed code golfer and a fan of ML-style syntax, I actually kinda like it myself; I was just listing a few things that are "considered questionable" (by some people) and present in both languages.
I still fail to see what makes this questionable. It's just syntactic sugar that you don't even need to use, and which is pretty clear when you see it in the wild.
As a bit of an unreformed code golfer and a fan of ML-style syntax, I actually kinda like it myself; I was just listing a few things that are "considered questionable" (by some people) and present in both languages.