There is no consensus among academics about whether people should seek to make their publications least publishable units, and it has long been resisted by some journal editors. Particularly for people just getting started in academic publication, writing a few small articles provides a way of getting used to how the system of peer review and professional publication works, and it does indeed help to boost publication count. But publishing too many LPUs is thought not to impress peers when it comes time to seek promotion beyond the assistant professor (or equivalent) level.
Also, LPUs may not always be the most efficient way to pass on knowledge, because they break up ideas into small pieces, sometimes forcing people to look up many cross-references. Multiple salami slices also occupy more journal pages than a single synthetic article that contains the same information. On the other hand, a small piece of information is easily digestible, and the reader may not need more information than what is in the LPU.