Actually, noting is incredibly important, especially since apparently in Shakespeare's time, the "nothing" of the title would have been pronounced as "noting." This helps highlights the way in which noting, or spying and eavesdropping, play a massively important role in the play. This play is one in which the plot and its complications (and resolution) are driven by various things that are noted, sometimes mistakenly, and some times correctly, by various characters.
Consider Borachio who "notes" the conversation of Don Pedro and Claudio and the way that Don Pedro and Claudio "note" the liaison of Margaret and Borachio, being made to think that they are Hero and a lover. Likewise, the stratagem of Don Pedro to bring Benedick and Beatrice together depends on both of them eavesdropping on a conversation that is being deliberately staged for them.
Remember too that during the ball scene of Act II, scene 1 Hero is wooed by Don Pedro from behind a mask, and whilst he is doing this, both Claudio and Don John and Borachio are "noting" what is going on, and all it takes is a few words from Don John to deceive Claudio into believing that Don Pedro's attentions are not what they seem.
Lastly you might want to think about how the transformation in Beatrice and Benedick is noted by their friends as they begin to fall in love, but how both rigorously try to pass off their symptoms as being an illness. Noting is something that is a constant theme throughout the play and is used to engineer and generate the main conflicts and humour in the play.