Bernstein: "this entire round (that is, primary elections open to mass electorates) is rare by world standards. Only a few nations that have adopted the American direct primary for any office, and as far as I know no other country combines a long ballot with the direct primary."
Whenever I talk to people who wish our system allowed for more parties, and thus more options in a general election, I tell them that they've got plenty of options -- they just have to get involved in primaries. If you don't like the positions of either party, you should support a primary candidate who can co-opt the party machinery and turn it in the direction that you want. For reasons I don't understand, they're usually not satisfied with that. So then I tell them that I like IRV as much as the next guy who's willing to give up monotonicity, and we talk about something else.
Often, my interlocutors were expressing a wish for a multiparty system where there are a whole bunch of parties on the ballot, and everything gets hashed out in parliamentary coalitions. I guess there are different ways of fulfilling voters' desires for more than two choices -- primaries and multiparty systems. Maybe part of the reason why so few countries have direct primaries is that when you already have a multiparty system, you've given enough scope for voter choice that you don't need primaries.