When the speeches are over, you get a grade. Often, you get graded on what you did wrong. This isn't a way to build reassurance and motivation. Then too, you rarely get much of a chance to practice by doing. You get up at the end of the semester, give your speech, and sit down.
Toastmasters is constant reinforcement and constant improvement.
You learn by doing, not by sitting there while someone lectures for hours. For-profit courses such as Dale Carnegie can be very good for their participants. They also cost a lot and when they're over, they're over.