But who can argue with arguments such as Fuck the Tories?

That statement is true and explains why we should support replacing FPTP, but doesn’t mean you shouldn’t vote tactically. Hating the system is reasonable, but playing the system is necessary whilst it’s in place. Otherwise you’re just weakening support for replacing it.

Note that I don’t mean tactical voting is always the best option, just that it’s not a tool you should discard entirely, at some point your tactical vote could get FPTP replaced, so don’t be too uncompromising.

It’s a method of maximising utility from your vote within a given system. In our system, every vote except the minimum necessary for the winner to win does nothing other than signal support for a given platform. You have to weigh up whether that signal is worth more than the gains from getting your preference of your two local big candidates to win. One of those decisions is much more likely to make an impact, but it’s making an impact that’s less aligned with my actual preferences.

Another issue is that there’s not really any way to stop your political opponents from doing it, and if they do then they have a huge advantage over every other party that is more fractured. They’re making that sacrifice of voting for someone less aligned and in exchange they’re getting that candidate to win every time with 30% of the votes, because the rest of the electorate is split ten ways.