Every idea you cite as stupid was once believed to be true. Respecting the right of people to make stupid statements makes it much easier for us all to realize someday which of own beliefs are stupid.
Aristotle believed women had less teeth than men. If someone states that belief now, is it wrong to say "no that's wrong", and then laugh/ignore them?
If someone stated that men and women have different numbers of teeth, why not encourage an experiment? It's not an absurd statement unless you've gathered evidence or trust the evidence you've read elsewhere.
The challenge in this case is that morality can't be determined objectively without reference to some other framework, which itself is likely subjective. So it doesn't tell us whether Eich can reason or incorporate evidence. He likely formulates his view from a different set of assumptions.