Systems of finance assign value. They analyze worth. Finance looks at opportunities and the risks in those opportunities over time. The result of that analysis determines what return is seen as possible.
Preferences, practices, and patterns of behavior shift well before norms shift.
If you are using norms to analyze opportunities and risk in a certain context, you are most likely wrong.
To assign value, investors look at performance in the past, then they project that out to the future, and then discount back to the present.