A valid criticism for moral absolutism is that?

A valid criticism for moral absolutism is that circumstances make no difference in moral evaluations.

Absolute systems of morality are unenforceable; and you can't get a unanimous agreement that they are valid. There are many points of view, and one really needs to understand the reasoning behind different moral systems to truly respect people from all cultures.

An example: Traditional sexual morality says that sex should be with one partner throughout life. These morals were developed when there was no Birth Control technology and peoples' life spans were probably 35 years. Now that life spans are pushing 80 and not everyone chooses to raise children why do we have to keep the same old sexual moral systems; when it is obvious that most people don't even follow them anymore.