Scientists like using R instead of because the language lets them get set up and coding quickly with RStudio. More importantly, the language, tooling, and ecosystem is very forgiving when it comes to code quality and style. There is good R code out there, but the R community generally lacks the wide acceptance of good coding practices you see with Python users: unit tests, sane dependency management, type hints, documentation, safe namespacing, etc.
It's really saying something when scientists think writing Python code is a pain, because Python's a pretty forgiving language, too.