If you really want to go this route with the discussion that's ok. Let's talk about disease, then. What's the rate of mental health issues involved in the population that comprises EMS providers?
If you consider this article (with links to resources included within) EMS providers in Canada have twice the risk of PTSD than civilians. Some resources put the rate of PTSD as high as 24% over the duration of a career.
This article from 2012 cites sources that up to 29% of EMS providers demonstrate post traumatic symptoms.
While we all agree that numbers are hard to find because no one is really tracking them this article cites a lower number than has been mentioned previously in this discussion for US based EMS provider suicide while acknowledging that this is likely hugely under-reported. But that number is still more than one a week
And this is just the discussion surrounding PTSD and suicide. This doesn't count or consider the numerous other mental health issues that plague EMS providers.
So here we are with limited numbers and information available. However, what information we do have suggests the risk of PTSD at more than twice the general population. It also suggests rates population wide as high as 29%. At what point, then, do you think the CDC's definition of "disease within a specific group of people over a period of time" is met?
Interestingly enough this discussion and the articles I linked pretty much shoot down your idea that we have lower rates as we see how precious life really is. It's seeing the frequency of the wasting of such precious life over and over again that drags people down.
To be honest I'm not entirely sure what you're driving at or why you're driving so hard. Whether you want to admit it or not this is a problem. It is more widespread than you want to believe. It affects way too many of us. Burying your head in the sand and simply acknowledging it as "sad", the same as one might comment on the passing of a public figure, only contributes to the problem.