First off, what makes you think that ancient bards had no commercial motives?
Perhaps one of the most annoying traits in arguments is to straw man someone else's position. In this case, you ask a question that has no relevance to anything I said contains an assumption that is nowhere present.
I was pointing out that a critical difference between remakes and ancient works of literature that repeat existing stories is that in the latter
case are dealing with corporations exploiting its intellectual property over which they have legal ownership.
There is nothing in that paragraph as stated, or in my earlier statements, to suggest that folk sagas had no monetary value, but that they have a precisely different
value for being retellings of shared folk tales (like heroic strong men doing impossible feats), the genesis of the world and its landmarks (from creation myths to specific histories of given areas) and legends that may have begun with a historical basis but have become considerably embroidered.
But it is a lot
easier to attack an argument that wasn't made.
The rationale for retelling these stories are basically different. The reasoning behind Shakespeare's MacBeth and Virgil's Aeneid do have concrete, political purposes - both are extolling purported ancestors to the present ruler, and the latter in particular is a heroic narrative of proto-Romans with their future enmity with Carthage given the colour of a doomed love affair as opposed to the more prosaic opposition of power that histories record. Virgil far preferred the Georgics and wanted the Aeneid burned, but - understandably - Augustus liked it too damn much.
On the other hand Apollonius of Rhodes wrote his Argonautica basically because he was a nerd's nerd, a resident of Alexandria in the Hellenistic era when its library was justly prodigious, and his work is written in an imitation of the Homeric style. The Greek tragedies were obstensibly staged for religious
reasons - that in the retelling of many myths they contained things people may believe in is often an important consideration (a more recent, Christian, and English language example would be the Mystery Plays of Medieval England).
And all these legends and popular stories were revisited diligently in Europe in the nineteenth century, with the rise of nationalism (and thus the need for nationalist epics). Hence Lonnrot's edition of the Finnish oral epic Kalevala, for example.
There are innumerable reasons these stories were retold. For their folk value, for their political value, for their popularity (and thus yeah, an eye for profit - Shakespeare being the obvious example here of a guy who worked for his living), for their religious importance, a fondness the tellers had for the topic, any mixed and matched combination of the above. Not all motives are somehow noble but what they are
Hollywood studios may have the rights to a Spider-Man film and want to maintain those rights. Or a comic company like Marvel may want its own line of franchise films. The anonymously written Fautsbuch, Christopher Marlowe's Doctor Faustus and Wolfgang von Goethe's Faust were not all written for the same label.