No doubts that silence is the great of source of strength, but listening is a power fool tool as well to posses. The lost habit and hardly considered to learn the skills.
In my observation, there are number of reasons why people don't listen.
1. Lack of patience to concentrate what other people have to say.
2. Superiority complex-one think's that his/her opinion or thoughts are far better than the other person. As somebody has rightly said "Big Ego have little ears".
3. Habit of arguing rather than listen, discus and solve problems calmly. People sometimes tend to argue much without listening to the whole story.
4. Too much talkative. It's perhaps the most common of reason why people listen less and speak far more.
There can be many more psychological reasons as well why people don't tend to listen the way they should be as its the major problem among many relationships that both or either parties don't concentrate and give sufficient time to listen and ponder over each other's issues. The inability of this lead them to devastating effects, both for the relationship and their personality. It is thus can be understood how important is to develop and nurture this art of listening.
Build patience, improve your ability to concentrate by going through different therapies and exercises, you can also get some professional help if you want, be generous and positive towards other people thoughts and be respectful to every one's opinion. You will feel so much better, so much fuller by adopting this in your personality, that you will never feel irritated again and bored.
Thank you for your time :)