George S. Ledyard
My teacher, Saotome Sensei once said "Aikido people are most angry people in martial arts..." While I am not a fan of the way mixed martial arts has gone, we need to be realistic about our Aikido. Aikido really has a hugely passive - aggressive culture. We have an art that is fundamentally about the study of connection but the art attracts folks who do not want to really connect.
But the reason for that disconnect (pun intended) is the key, I think -- I may not be representative, but a huge part of the motivation to seek the art was simply not liking the violence I suddenly discovered lurking in me at a very young age, and explosively expressed one unexpected day and which appealed to me deeply in a troubling and darkly seductive way. That coupled with a slowly dawning realization that I could never possibly in any way actually extinguish it. So I had to harness it.
The type you describe, I think, imagined that they COULD extinguish it -- and so it snuck up and bit them from behind while they were not paying attention.