I am making two points:

-Arguing that adding a feature is ok because "R does it" is comically wrong when one is acquainted with all of R's warts and superfluous stuff

-Not even the R world uses that feature either, so we have actual empirical evidence that it's not that helpful to developers.

I wouldn't say an additional notes section at the end of article showing that is syntax is not unprecedented is an argument that the feature is ok because R does it. The author is simply giving additional context to allow readers to form their own opinion.

It's fine to not like the feature–I don't know enough about its usecase to feel one way of another–but your comment felt unnecessarily negative without adding much to the discussion.

Knowing that R users have access to these syntax and choose not to use it is interesting to consider, but that was overshadowed by your first statement.

R is a very...haphazard language. Not to say it isn't elegant in places, but I wouldn't describe it as a consistent, well planned language. I suspect it's not the rightward assignment OP has an issue with, but the fact that they're looking at R as an example to follow.