That's the problem with unknown unknowns. You cannot define them. We just know they exist, because the first thing science teaches us is the vast amount of thin

That's the problem with unknown unknowns. You cannot define them. We just know they exist, because the first thing science teaches us is the vast amount of thing we are ignorant of. What you can define, however, is the asymmetry of risk. For example, if a system is very complex, introducing series of intense rapid changes to it has chances of creating a strong disturbance because of cascading compounding effects on dependencies of said system. And because of the sheer size of the system, we cannot model it all, and hence we cannot predict such consequences and certainly not protect ourselves again them. If you highly depend on the system stability, then a strong disturbance has in turn a high chance of being in your disfavor. Nassim Taleb as a great bit about this his incerto. In the case at hand, the asymmetry is in not in our favor, and we should be prudent. And we are not being prudent. I'd say the irrational hand waving is rather from the people driving blind, yet stating we are doing just fine because most of the time we are arriving at destination just fine. Especially since the first people stating we are doing just fine are the ones that have a huge conflict of interest in the matter: the ones performing the changes and expecting to benefit from it. Now I understand that often the debate is full of facebook mums, which doesn't help giving a lot of credibility to the argument I'm raising right now. Still, I think it's important we remain alert and objective about the matter, and I don't think any side is. Certainly not when so much money is involved.