There's something oddly enjoyable about creating haikus; delightful little things really. To fashion a haiku one does not need to employ polysyllabic nor bombastic words, because little poetic skill is required. Heck, even a six-year-old could do it with ease. Furthermore, they are really versatile - they can be about anything under the Sun ranging from the most insipid things to the level of philosophic thinking (although this may be true for most other literature). That's probably what makes them slightly more appealing than palindromes and limericks; they're simple yet effective.