That ideology provides cover

Eco writes about Dante’s project De Vulgaris Eloquentia (in which Dante discusses the perfect language and his project to make one on the basis of the Tuscan dialect):

For someone of Dante’s temperament, the conviction that Adam’s Hebrew was the only truly perfect language could only have resulted in his learning Hebrew and composing his poem in that idiom. That Dante did not decide to learn Hebrew shows that he was convinced that the vernacular that he intended to invent would correspond to the principles of the universal, God-given form better even than the Hebrew spoken by Adam himself.

More likely, in my opinion, it shows that the proposition to learn Hebrew well enough to compose poetry in it was simply too daunting: Dante did not think he could do it. True, he had learned Latin, but Hebrew was then the far more difficult language to learn; it was nothing like Tuscan; there were few teachers; opportunities to practice were scarce. Nor would there be any readers.

Besides, Dante was already old by linguistic standards: we lose the ability to learn language like a native around puberty; and from then on with every passing year it gets harder because the brain dismantles and recycles the language learning device. And then we find ourselves in the mortal situation: it is too late for it; all we can do is wish we had thought to do it back when it was still possible. Or manufacture theories explaining why it isn’t necessary to do it after all.