From the Editor’s note:

“I tried to keep to Shelley’s unusual (and non-standard) rhyme scheme for the sonnet, but I departed from it in the second-to-last line for poetic reasons. For a language which excels in stealing words from other cultures, English has an appalling lack of rhymes.”

Perhaps with deeper analysis, and a few choice new words this issue could be remedied.

Although that’s a paradoxically tedious engineering solution to improve a languages beauty.

From another angle how comes other languages are more poetic, are they older and have had more time to evolve to be more poetic? Or were the speakers who wrought the language just more poetic.

Yes! Thank you!