Adam,
I understand what you're saying wrt some standards being too high. However I think it would be incorrect to state that medicals only exist due to vested interests from the medical profession! I think in fact if you look into the history of medical regulation in aviation you'll find that's not the case.
I's also be interested to know where you found your data to support your statement that medical regulation does not prevent accidents or make the sky a safer place. Furthermore, you are correct, no one can predict when a heart attack will happen but cardiovascular risk can be calculated based on certain physiological and biochemical parameters and I would argue that this is a valuable tool in predicting the likelihood of a heart attack within a certain period of time.
I agree entirely that some medical standards are too strict. Some of the standards lag way too far behind the research and consequent advances in medical therapies and disease prevention. Unfortunately this prevents some people from flying who arguably should be allowed.
However, surely you must see that doing a complete 180 is not the way to go. Surely a pragmatic and carefully considered approach to reviewing the standards should be undertaken and this would be a responsible way to assess medical fitness for the safety of the pilot, those they may be carrying, others in the air and those on the ground.
Piloting an aircraft and driving a car is not the same thing, at all.
Just my opinion.
B