The original question had to be edited. I would suggest that one reason as to why the poem is likable is because it shows the power of imagination. The speaker, presumably Wordsworth, hears a song from a woman working in the fields. He stops and allows his imagination to be carried away by the song. His imagination takes him to the sands of Arabia, the Hebrides, and reflects about battles, sorrow, loss, and pain. The poem's simplicity is where its likability resides. Wordsworth need only hear the song and his imagination transforms reality to what could be from what is.
The tenets of Romanticism in terms of being able to appreciate the most basic elements of consciousness as part of daily life is a moral out of the poem. This is where the poem is likable, as it resides in the most simplistic elements of being in the world. The poem speaks to the importance of recognizing that there is magic in the most basic parts of existence. Wordsworth conveys the need to open one's imagination to all the beauty that exists in the world in order to better appreciate our own place within such as marvelous configuration. To borrow from Tennyson, "That which we are, we are," and we cannot change the conditions of our being. Yet, through our imagination, we can find beauty in it and it is here in which the poem can be seen as likable.