If you think about how many MILLIONS of people visit a Disney Park every year, someone is going to have problems there. Doesn't necessarily mean that Disney is at fault, just the timing.
For example the last couple of deaths have had NOTHING to do with the parks! People just unexplicably pass out, have heart attacks and die.
While I am very sorry for this happening to these people, I think these tragedies would probably occured at the same time no matter where they were.
I think that considering the amount of guests, the amount of deaths is incredibly low! Just my thoughts