I don't believe the prompts are falling short, so much as they are just subject to each poets process. My poetry, for example, primarily uses personification and metaphor. I choose objects/subjects, and then form their relationships to my emotions and thoughts from there. So 'love' and 'laugh' as prompts simply didn't suit my own prefered process, but other poets may work vice versa, requiring the emotion before fleshing out the subjects/objects. It just depends on your users' process habits.