Cuenta John Chambers (el creador de S, el lenguaje del que derivó R) en “Software for Data Analysis”(2009)
“Creating a function in R is extremely simple. Users of R should quickly get into the habit of creating simple funcions, which will make their work more effective (through adaptability to related problems and ease of modification) and also more trustworthy (through a simple interface and freedom from side effects)”.
Así que quien no escriba funciones en R, ya está tardando.