You will one day be part of the "no-longer-productive" demographic. Do you have the million or so in savings it takes to stop working?

I'm 77. Happily, I don't need a job. But if I did, I'd certainly understand why an employer would be unwise to spend time and money on hiring a person with my life expectancy.

There are good policy reasons for age discrimination laws addressing the younger ages, but they are essentially extensions of wage-and-hour laws, not civil rights laws. That's why the tests should be different.