CC Antya 5.102
siddhānta-viruddha śunite nā haya ullāsa
Yadvā-tadvā kavi refers to anyone who writes poetry without knowledge of how to do so. Writing poetry, especially poetry concerning the Vaiṣṇava conclusion, is very difficult. If one writes poetry without proper knowledge, there is every possibility that the mellows will overlap. When this occurs, no learned or advanced Vaiṣṇava will like to hear it.