Agreed.
Although, to be fair, the quote was misapplied by assuming only lessons about humanity count, and ignoring the Giant saying worlds that differ from ours (dragons are not human) don't invalidate the lessons. To be honest I would prefer to have a story about dopplegangers and warforged that teaches lessons about personhood rather than a story about humans that teaches lessons about the era's current overly narrow understanding of humanity. When I'm old, a lesson about personhood is likely to be more applicable to humans and likely to be less dated than a lesson about humanity.
However, yes I agree that entertainment can have value without teaching a lesson. It need neither be petty nor escapism.