If you just want to go fast than it would be much cheaper to pickup a kiteboard or windsurfer ($$/kts ratio).
The cool thing about sailing for me is the competitive element where all out speed is less important for the overall experience.
Very true..... and I would add... the ability to sail with a team mate adds to the complexity and fun factor as well.
Finally.... I have never gotten a request from a kite board or a sailboard to compete in one of our point to point races... Boats make this doable. (now Billie... boats with cub holders..... THAT is what you should take some grief on!)