I agree they should have been wearing them.
The second part of your statement is disturbing to think about. This is really sad.
The thing is that seasoned citizens are usually able to swim or at least float on their own. They might not be fast anymore, but they know how to tread water and don't usually panic.
It will be the next law Big Brother forces on us. No one allowed within 50 feet of water without a life vest. Thats includes the boat rides at Disney World.