1. Good for health. The waters help rejuvenate the skin.
2. Visit the lowest point on the Earth's surface.
3. Float on the most naturally occurring saline waters. The Dead Sea has the highest concentration of salt in its water compared to other places on Earth.
4. To relax. There are a lot of spas nearby.
5. To support the Israeli or Jordanian economy, depending on what side you go on.
6. The Dead Sea is drying up. So you might as well see it before it could disappear!
7. To build a sandcastle on it's beaches (well, if nothing else, it's fun to do).
8. To buy products made from it to take with you (kinda like 5, except this is specific to the sea and not just all of the nation... and you might want to ignore that you can buy these products elsewhere too).
9. To use it as an excuse to drag friends or family members on a vacation. The dead sea is great for group activities.
10. To take interest in it's unique environment and the history surrounding it. Others mention Masada and Qumran, which are good places to visit too.