I think in his time period, this was considered something more radical than it would be today. Now, everyone is trying to find a way to stand out. Just look at all of non-traditional names that celebrities are giving their babies.
I think he attained fame not only because of his non-traditional use of punctuation, but also because of the quality of his work. His rejection of what we might consider traditional uses of punctuation, spelling, and grammer demonstrate a sort of rebelliousness. What might be traditional punctuation to one person, might be a stultifying use of language for another. A poet presents thoughts and sentiments in a distilled form, so to be bound by rules of language use would be to hobble one's self. Why deny yourself the freedom to play with language, sound, tempo, and more? That's why I love poetry!
My favorite poem of his will always be "anyone lived in a pretty how town." The musicality and rhythm of that poem stands out and makes me wonder how long it took to compose.