Yes. You should put the brick where the engineer tells you too, and at the end of it you will observe there are more bricks than were strictly needed. Any other approach would be reckless.
Again, you're arguing that the rational thing to do is to not build the thing properly. You've misunderstood rationality and you're getting nonsense conclusions where people choose to get to get poor results by their own standards because they aren't very good at risk assessment. That isn't how rational actors behave. Rational people take a holistic view of all the foreseeable costs and benefits of an action (like, for example, having a government that aligns with their policy preferences) and are capable of probabilistic thinking.
> In all likelihood many won't bother without being directed, encouraged or otherwise socially motivated.
Well sure, but in practice people aren't rational. If they were rational, they would just quietly assess whether their coalition had the potential to win at some point and - if so - identify that it is in their best interests to vote. Then do it without prompting.
> Given you previously mentioned Game Theory, this is a surprising claim. Prisoner's dilemma? Tragedy of the commons?
The game theoretic optimum in both those cases is to achieve the best possible result through communication and coalition building.