I agree with Nikki re: the numbers being off and also people getting Riluzole earlier.
Another thing I think helps is better utilization of supplements, MMJ and exercise. I still run into medical people who advocate a "do nothing physical at all" approach because you only have "so much left". Basically the between the lines is "There's nothing you can do except sit around and wait to die" -which really ticks me off...
The other thing I intend to discuss with them at the clinic next week is weight loss/gain. Don't get me wrong, I truly believe that keeping my weight up is important BUT adding weight as fat as much as possible doesn't make sense to me.
Here's my reasoning - I'm going to lose X amount of muscle via wasting and atrophy. Replacing that weight with fat just makes it harder on the muscles remaining not to mention the increased likelihood of falls, breathing effort, etc... I realize that a healthy weight needs to be maintained for your immune system, etc... and the neuroprotective qualities of a high fat diet are another reason to maintain a good weight, but I've had a couple of people in clinic suggest what essentially would amount to blobbing out (now that I think about it these tend to be the same ones that advocate no exercise) and I've witnessed first hand the degenerative effects of that with my Mother. She has essentially become wheelchair bound due to weight gain and muscle loss due to a lack of exercise) even though her motor functions would allow her to walk if she was a normal weight.
So LSS, I think another reason for increased expectancy is people re-thinking the conventional wisdom and individualizing their management of their "personal" version of ALS.