I have a neighbor who used to work as a landscaper. The money was decent (in SF); his specialty was masonry. Then a couple of years ago, he decided to drop out. Claimed he had MS and started getting SSDI checks of about $2K/month (I think). After he dropped out, I've seen him lift 100lb stones; frequently, he'll drive down to Arizona for fishing trips with buddies; and recently, he drove cross-country to Georgia for…
Yeah, screw him for living life to the fullest while he still can, instead of continuing heavy physical labor every day until he's in a wheelchair.
In all seriousness, it's not like disease is completely black & white and there's always an obvious day up until which you can easily work. Just the mental & emotional drain of coping with something like this must make it incredibly difficult to get up every day and get excited about working.
If our economy can't provide a safety net for people in tough in-between situations like this, then let's make our systems more efficient rather than force a bunch of people to do something they don't feel up for just because it's a job.