@crowriver It's quite the opposite. By ranking all the candidates, my understanding is you kinda "dilute" everyone else's vote who's doing the same. Since a lot of people only vote for their preferred party and leave the rest blank, or only use their first and second preferences, that can increase the chance of some batty wingnut sneaking in on transfers.
It's better to look at it as first you pick the candidates you want, and when you run out of those, then you begin voting against those you absolutely don't want.
For example, for all their heel-dragging and simpering and petulant demands for "more consultation", I'd still take a Lib Dem over a Tory(paper thin though the distinction often is these days), and I'd certainly take a Lib Dem over a rabid climate-denialist Libertarian(from what I can tell that's not party policy per se, but an awfy lot of their candidates on social media do seem a bit flat-earthy on the subject), or the Family Party bigots. By ranking everyone, you ensure that your vote is always used - either for the candidates you want or, if they don't make it, at least against the ones you don't.