Not really. You've asked very generic questions regarding health conditions and have made an assumption that all of those health conditions were cleared for diving. I'm no doctor but I do know that a "stroke" (there's a joke in here) can be defined many ways and have many causes, not all of which would be cleared for diving. Same with the laundry list of other ailments you seem to believe get a blanket clearance.
Add to that, your assumption that those "individuals" were cleared for diving, may not have been or they may never have asked or told their doctor(s). Shocking as that may be, I mean, people not being completely honest to their doctors?
And I'm just as bad, after a very bad bike accident, where i sustained a "minor" head injury, and going to the ER, l never told the ER doc about the head issue, last thing I wanted to have done is been put on some concussion protocol! Nor did I ask about when I could dive again! Heck, I've had a piece of "shrapnel" in my leg from an industrial incident for years and years, never once did I even ask if I could dive with it? Why?
Point is, you've made a lot of assumptions to attempt to validate why you dont have to listen to your doctors. That is obvious.