The advice is common enough that it has a wikipedia page: https://en.wikipedia.org/wiki/KISS_principle.

There is no gatekeeping. There is a suggestion that C is best used for projects that have builds no more complex than a Makefile configuration. There is explicitly no ~judgement~ limit on what ~kink~ text editor one may use to edit the files.

thus hegemonic institutions reinscribe the kyriarchy generation after generation by perpetuating a hierarchical opposition between "knowledge" and so-called "ignorance", which is socially constructed to be inferior, less than, but which serves the purpose of distinguishing the graduates of elite institutions (to which access is mediated by the financial privilege of the bourgeoisie) from the subaltern underclass; thus "knowledge" serves the interests of capitalism by reproducing oppressive class divisions, enabling the continued exploitation of the working class

what could be more problematic than that?

but if you're interested in learning something and not just playing word games to gain status by putting others down, i problematically mansplained what you're missing in https://news.ycombinator.com/item?id=37083233

I'm guilty as charged. The advice is not discouraging unless you really want it to be.