Yes, part of an accurate description is identifying the boundary conditions within which that description applies, and applying it outside that boundary is asking for trouble. Agreed.

I don't see how this is any different for folk morality than for folk physics, folk medicine, folk sociology, or any other aspect of human psychology.

For my own part, I find that formalizing my intuitions (moral and otherwise) is a useful step towards identifying the biases that those intuitions introduce into my thinking.

I also find that I want to formalize other people's intuitions as a way of subverting the "tyranny of structurelessness" -- that is, the dynamic whereby a structure that remains covert is thereby protected from attack and can operate without accountability. Moral intuitions are frequently used this way.