As many of the other posts noted, most students will eventually find themselves in a position where they will have to speak in public sometime as adults. The presentation of a speech is a way to build confidence and prepare for future public speaking opportunities. It is also an excellent manner for researching a subject and then writing it in a style that fits an oral presentation.

I believe that speeches in school are necessary. All aspects of speeches speak to the basics of education: planning, research, and correct grammar. I, too, was scared to death of speaking in front of my classes. After much practice, I learned to overcome these fears--another important educational aspect.

When I was at school I avoided speeches at all costs, and was pleased with my cleverness- right up until I became a teacher, and found lots of the preparation for class delivery gruelling. I explain this to my students now, and I tell them speeches get easier with practice, and starting early makes more time to get it right.

 After 19 years of teaching, I can say hand on heart that students DO get better when they try, ARE more confident when expressing themselves verbally and can become proficient at getting their points across clearly.

We are constantly challenged in life by things we fear. Facing up to such tasks, breaking them down and overcoming them is part of life.

Speeches in school are valuable because they require thought, planning, practical preparation, and a certain amount of courage.  (Publically speaking is a task that many people fear.) All these requirements will be useful later in life, even if one doesn't make a career of public speaking.

Just like many of the skills mandatory for high school graduation, you may not use your experience giving speeches later in life, but then again you might.

In order to really keep your options open for the future (where you may change your mind a hundred times about what you want to do), high schools demand that students master a set range of skills.

If they didn't, students could find themselves unable to pursue the goals and passions that develop later on. You might feel forced into giving unnecessary speeches now, but what if you decide that you want to be a PR person in ten years, or be the spokesperson for a company? You'd be glad then that you had some experience and a knowledge base in public speaking.

Many people identify speaking in front of groups as one of their biggest phobias. Giving speeches helps students overcome this fear through simple practice, and more importantly, through learning how to make arguments and support them with facts and data. I would argue that speech-making should be a larger part of school curricula than it is.

The main purpose it serves is to get you used to communicating with other people in a public setting.  That is going to be important in your life if you end up having to do things like having business meetings with groups of people who might be potential customers or potential investors in your company.