If we analyze the phrase, we can see that "Let me be like wheat in wind, bending just so, Not the weak-stemmed daffodil, bent in rain, Dipping its face in mud churned by a workman's clogs." is actually an excerpt from Gary Soto's Hamlet 1.3.78 which is part of a collection that begins every poem with a line from Shakespeare's plays. There's a poor man who is in love with a woman. The woman is rich and out of reach, since he wants to be like a wheat in the wind instead of a weak-stemmed daffodil.
One can say that he just wants to be noticed and even though the daffodil might be more beautiful, it might be unnoticed, which is what he does not want. He wants to at least be seen, even if he doesn't get much from it. At least he'd have some attention from her. Another way to see this is that the woman should consider his affection in a positive way instead of taking something beautiful and throwing away into the mud.