I might be reading this wrong, but it seems to me from your description that your grandfather simply did not get "ticked off" by the same things as your grandmother. Those topics do not seem to have generated strong emotions in him. But they seem to have done so in your grandmother.
What raises strong emotions in people seems to be highly subjective. To what extent you are able to have those stronger emotional responses while at the same time not succumbing to the impulses that go along with them, is what I would argue determines your ability to tolerate the stimuli that generate these emotional responses.
Since these responses are physiological, rooted in our survival instincts, they greatly affect our ability to be rational, open, and contextualize. Instead, they move us into increasing levels of black-and-white thinking and fight or flight, first mentally, then physically.
Whenever I explore topics that stir up strong (negative) emotions in myself, I find that they are usually tied to this, if I can get deep enough in my exploration.
After all, we're just animals trying to survive and procreate, even though we have become very elaborate and ornamental in our pursuit of these goals.