Here's why:
* Multiple Versions: There are numerous versions of the "Bernardo Carpio" story, with different poets and writers contributing to its evolution over time. This makes it hard to pinpoint a single author.
* Oral Tradition: The story of Bernardo Carpio likely originated in oral tradition, passed down through generations before being written down.
* Early 19th Century Attributions: Some scholars attribute the earliest written versions to Francisco Baltazar (also known as Balagtas), a renowned Filipino poet of the early 19th century. However, there's no definitive evidence to support this claim.
* Later Adaptations: Many later writers, including Jose Rizal and Lope K. Santos, have also contributed to the story's development and popularization.
Therefore, attributing the authorship of "Bernardo Carpio" to a single individual is challenging, and the poem's origins lie in a complex tapestry of oral tradition and various literary contributions throughout history.