> Sometimes the breakdown does look disturbingly similar to
> the old traditional gender roles
That seems somewhat inevitable. A lot of those gender roles are there precisely for comparative advantage and "do the thing that annoys you less" reasons. It just happens that statistically fewer men are annoyed by trash (e.g. they never get pregnant, so don't have months-long periods when they just can't deal with it at all), women are better at taking care of infants (e.g. can often feed them more easiy), and so forth. On average, etc. ;)
The smell is part of it. For some women also the sight, or even just the thought of either one. On average, pregnant women tend to react much more strongly to anything rotten or possibly-rotten; the details will tend to vary from person to person, of course.
That seems somewhat inevitable. A lot of those gender roles are there precisely for comparative advantage and "do the thing that annoys you less" reasons. It just happens that statistically fewer men are annoyed by trash (e.g. they never get pregnant, so don't have months-long periods when they just can't deal with it at all), women are better at taking care of infants (e.g. can often feed them more easiy), and so forth. On average, etc. ;)