Much talk is made of how Gilgamesh is a Designated Hero for killing the sacred guardian of the Gods' Cedar forest purely to get famous for doing so. However, considering that the central aspect of Gilgamesh's character is that he's an immature Manchild who needs to grow up, perhaps we were never even supposed to side with him on this matter?
From afar the whole thing reads like a deconstruction of power-fantasy plots - first he does some awesomely manly things, and an equally immature listener (it was originally an oral epic) goes green with envy, then it turns out he was behaving like a manchild. So yeah, probably intentional. Maybe one of the missing fragments even actually tells how he was chewed for this later on.
