Good question.

Clearly, individuals vary in their ability to tolerate risk and uncertainty. Some are much more tolerant of the risk to others than they are of risk to themselves, and visa versa. The 'angle' or perspective from which the risk assessment is done, which may also have to do with the purpose of the risk assessment is a factor. The level of psychological denial is a big factor, as it determines the perception of risk. Too much denial or too little are equally problematic, but who is to say what is just enough?

Who "we' is will be a factor. "Our" resources will be another factor - both the nature of those resources, and how plentiful those resources are. Values and mores play a significant role,

To live is to risk. To move in the world is a risk. To allow a child to get in a swing, or to climb a tree or monkey bar is a risk. What risk is actually being assessed? In your example regarding the sculpture, if "we" is the corporate entity of the library, then I assume the risk being assessed is the risk of being sued. Which is related to, but not the same as the risk that a child might be hurt.