Why? Why does someone allude to a point without saying it. Perhaps because even mentioning it brings with it a certain level of controversy and thus speaking about it indirectly allows more focus on the topic at hand. Also, while there is one in particular, there are other needs listed that are often not given the full consideration (though the others rank higher of the hierarchy, and thus if the discussion is only on ensuring people have the lowest level met, the other needs aren't within scope).

Your comments are vague to the point of being useless.

I even went to the bother of trying to look up what it is you'd be referencing, and came up blank.

I think you are severely overestimating the likelihood that anyone knows what you are talking about.

I'm fairly sure they're talking about sex or intimacy, which Maslow had at the base of his hierarchy of needs