Love!

"R is a shockingly dreadful language for an exceptionally useful data analysis environment. The more you learn about the R language, the worse it will feel. The development environment suffers from literally decades of accretion of stupid hacks from a community containing, to a first-order approximation, zero software engineers."

Yup.

The first time I tried to read R code I was immediately disgusted with how '.' is a valid variable name character. Not only valid, but inexplicably also in common use.

That's in part because, unaccountably, '_' denotes assignment in S.

> unaccountably

Maybe because in ASCII-63 the _ codepoint meant left-arrow (which was preserved in at least smalltalk systems much past the 60s)?

My theory is that they might have been trying to protest against the non-mathematical theft of = (equality) to mean assignment, as = is used in most other languages. (Not that that's an excuse for violating the shit out of the Principle of Least Surprise in a trillion different ways.)

It's immature to rail on R for things like how its syntax doesn't look like that other language you already know, but yes, it's extremely quirky. And its unchecked flexibility, while great for experts providing DSLs and such, enables non-programmers to produce garbage implementations. The vast majority of R's myriad community packages (R's biggest strength!) seem to be written by a grad student who read half a tutorial.