Not everything that comes out a person's mouth is a proposition, nor does it need to be. If people don't vomit from time to time they asphyxiate and die. The type of rationalism that polices all verbal behavior to the standard of science is counterproductive.
It's usually contextually obvious, and many of the memes of rationalists demonstrate this (like the concept of "cheerleading" or "pseudo-belief"). They point to some function of speech other than truth content, say "I don't like that function", and conclude that must make it bad.