1. It's expensive.
2. They don't take credit cards.
3. It might require a chiropractor, later.
4. Things stain.
5. Longer life batteries? By whose definition?
6. Some muscle cramps can't be kicked out and will require medical intervention.
7. It's not funny.
8. A picture lasts forever.
9. Clothing optional is not always an option.
10. Again, it's very, very expensive.