>>...But would coders even know how to write emotional code?
We need to define what emotion is, exactly, before anyone tries to code something that works a bit like that. It seems what we call 'emotion' is still an open question physiologically. Is it hormones influencing thought? How does that happen? And what do we mean by 'thought'? Resonant electrical patterns? There's probably more to it than simply synapses firing, and the receiving end acting as a 'difference engine'.
Software guy here, and lesson one is to not try to build something if the client can't define what they want. There are ways to build prototypes that might get better answers out of your client; that's off-topic here (but I have horror stories)...