If only Hadley hadn't picked snake-case, which doesn't work so well out of the box with ESS. Yah, I know there is a way of fixing this with a setq in ESS, but I shouldn't have to.

Always weird to meet Emacs people who don't like having to customise Emacs. That said, ESS has some weird defaults, not sure I'd lay them at R's door tbh.

ESS defaults predated Hadley's contributions by a decade, making his seemingly unique adoption of snake case extremely unsociable. I actually use _ to <- a lot. It's enough of a pain in the ass, I basically stopped using his packages. This was annoying, but ultimately the Hadleyverse became a bridge too far for the kind of bread and butter data science I do, so it turned out to be helpful to me personally.

ESS disabled this behavior by default a couple releases ago, so it shouldn't be a problem anymore.

I agree. But I'd also argue that it's based on how you're using the tools you're given (or what others have given you).

Pretty much the argument of using apply vs for loops. Most of the time, apply is going to be significantly more computationally efficient. However, some people think of the problem in different context than others, and if it works for them then it works.