1. Because they do wonderful things for your confidence.
2. It is nice to have a weapon on hand in case of a zombie apocalypse.
3. How else will you get the cat to listen to your pleas?
4. They are cool.
5. You have an empty space on your wall.
6. It is tradition to receive one on a certain birthday.
7. You are the Chosen One.
8. It helps you get into character.
9. Swords make for excellent conversation starters.
10. A sword will help you get to the point.