Every speech, whether terrible or terrific, is an opportunity for you to learn. If you listen to just the content, the message, you are missing much of the learning.
If you are an auditory learner, focus on the techniques used. A speaker has only 30 seconds, or less, to make a positive impression on the audience. If he makes a negative impression, the attendees will soon ignore him. What techniques does he use to make the necessary powerful introduction?
How does the speaker keep the audience focused and thinking about his message? Statistics are like spices; use too much and many people wince. What techniques does he use instead? Is he confusing causal and coincidental cause and effect?
How is the speaker's voice quality? Does he sound bored or excited? Is he using pauses effectively, or not at all? Is he loud enough (hopefully with a microphone) to be easily heard?
How does the speaker transition from one topic to another? Is his ending wimpy or wonderful?
If you are a visual learner, how are the slides for the speech, if there are any? Are the gestures distracting? Does the speaker have great eye contact, or is he (gasp!) reading his presentation and therefore avoiding any eye contact and the chance to connect with the audience? Are any handouts helpful? How is the audience reacting to the presentation?
This is a season of powerful presentations. Whether you listen to President Obama's farewell presentation, Martin Luther King's amazing "I have a dream" speech, or someone else's talk, make the effort to consider what he or she did well or poorly.
Your time is valuable. If you are to listen, get something out of the experience!