The problem is that those warnings are so pervasive that most people ignore them, and many healthy people would perhaps be included in them. Everyone has had some health problem. I went to the ER eight years ago with a hearth rhythm problem. I cut down on caffeine, upped my exercise, and never had another episode. Does that mean I shouldn't ride Star Tours? Of course not. The only rides that messed with me at all were Space Mountain at Disneyland Paris and the Teacups, which didn't stress my heart at all, just my stomach and semi-circular canals.
I would hazard to guess that reading every single warning word for word at WDW would take hours, if not days. For sanity and time sake, we ignore them. Does anyone actually read all the junk that comes with your phone bill, credit card bill, or utility bill? Of course not. None of us would waste that time. We have better things to do. Similarly, none of us can be expected to read all the warnings at Disney.
Right now, I am 51 years old, 6'0", 225 pounds, have a stressful job, and I once went to the ER with a heart rhythm anomaly. If I died after riding Small World, they would write up that a middle aged stress out overweight man with a history of heart disease died on Disney's tamest attraction. Call OSHA. Convene Congress for an investigation. Field the solicitation letters from law firms. If all of us with health problems shunned the rides with overly inclusive warnings, they would be half full, at best.
The poor man died because his time was up. Not a bad way to end our time on earth. He, like the rest of us, had health issues and was imperfect. Let's just pray that the family is managing it well, and that the man had his business straight with God.