Handicap?

There was an article in the San Francisco Chronicle that talked about how parking meters in San Francisco were not collecting as much money as expected, and a conclusion was that there are too many people with handicap placards (who are allowed to park for free at meters). Something like 90,000 people in San Francisco with handicap placards, but only 23,000 parking meters.

So, how does one get a handicap placard? From the California DMV site, it says that a person with one of the following can get a handicap placard:
1) Heart or circulatory disease.
2) Lung disease.
3) A diagnosed disease or disorder that significantly limits the use of lower extremities.
4) Specific, documented visual problems, including low-vision or partial-sightedness.
5) The loss, or loss of the use, of one or both lower extremities or both hands.

Two of these surprise me. Heart disease has become very common, and one of the causes is a lack of exercise. So allowing them the privilege of parking right in front of their destination sounds counter-productive. Shouldn't we make them walk so they can improve their condition?

And people who have vision problems - should they even be driving?

It would be interesting to see statistics of what percentage of parking placards are given out for what cause.