"Outside view" refers to some threshold of reliability in the details that you keep in a description of a situation. If you throw out all relevant detail, "outside view" won't be able to tell you anything. If you keep too much detail, "outside view" won't be different from the inside view (i.e. normal evaluation of the situation that doesn't invoke this tool). Thus, the decision about which details to keep is important and often non-trivial, in which case simply appealing to something not being "outside view" is not helpful.