In what way is the speaker's simple ignorance a profound wisdom?

The speaker in Emerson's poem "The Rhodora" contemplates why a rhodora blooms in an obscure wooded place where there is no one to appreciate its beauty. He thinks the rhodora's beauty rivals that of roses and would make a cardinal's natural beauty pale in comparison.
When the speaker tells the rhodora to tell anyone who asks why its beauty is "wasted on the earth and sky" that "beauty is its own excuse for being," it is evident that he has already figured out that beauty does not need a human appreciator to validate or quantify it. In fact, he reflects that it never occurred to him to think about why the rhodora was there, but now that he is thinking about it, he figures that whatever has created the rhodora has created him and, likely, everything else that exists in the natural world. This "simple ignorance" could be called unspoken faith, a sort of bone-deep or intuitive recognition that we and all that surround us are expressions of something greater than ourselves.