Not accepting women as equals is NOT COMPATIBLE with democracy. If your believes rule out rights for 50% of the population, you also don't deserve living in one. Physically attacking the female flight attendant shows this isn't something about "beliefs about cross-gender contact", its about seeing women as inferior.

Same tale as with fascism: total tolerance leads to the extinction of tolerance, which means we must be intolerant of people like this disgusting chud.

There must be a mechanism to remove such people from societies where they only inflict damage. Sadly simple removing his citizenship is not legal, but i'd approve of any measured approach to make him realize that living where people regardless of gender have the same rights might come at a cost that is too high to pay.