Open primaries invite strategic voters to sabotage the party they want to lose rather than supporting the candidate they want to win.
Of course you can still do that with closed primaries—you just have to register as the party you want to vote for in the primaries, ignoring your own preferences. Nothing forces you to vote for your registered party in the general election. It’s slightly more involved this way since you would need to change your registration more frequently, and commit to it earlier, but that isn’t much of a hurdle.
Open primaries invite strategic voters to sabotage the party they want to lose rather than supporting the candidate they want to win.
Of course you can still do that with closed primaries—you just have to register as the party you want to vote for in the primaries, ignoring your own preferences. Nothing forces you to vote for your registered party in the general election. It’s slightly more involved this way since you would need to change your registration more frequently, and commit to it earlier, but that isn’t much of a hurdle.