I wonder why the world is so tolerant of people who wouldn't shake a woman's hand, when there would be screams of outrage if someone said "I didn't want to shake her hand, because of her race".
Well, as vehement as I am about most things that I perceive as sexist, I actually do believe this one can go either way. The thing that gets confusing here is that handshaking is both 1) a certain level of intimate physical contact and 2) a sign of respect.
If a man refuses to shake a woman's hand because he believes that women are not worth of respect (and would similarly not bow to a woman, for example), then i think it should absolutely be treated the same way as your quoted example.
However, if a man truly simply wants to avoid what he considers an 'intimate physical contact' with a woman he's not related to (or married to), that's altogether a different kettle of fish. Similarly, if in a particular culture it is common to kiss friends on the cheek, or even the lips, in greeting, but you are uncomfortable with that level of intimate physical contact with someone of the opposite sex who is not your partner, I wouldn't think it *automatically* disrespectful to choose not to engage in that particular ritual.
A genuine problem here though is that it can be difficult to separate one stated reason from the assumption that the other is the true underlying cause....