Yes, good rant. I'm rather persistently annoyed by this sort of thing: the constant "splitting to the left"(*) in (the Republic of) Ireland, notwithstanding that no sort of remotely left-ish party or grouping has ever achieved a plurality here, much less an electoral majority. Yes, I think their policies pretty milquetoast and half-hearted too, but can we please try to walk before we run, here? Or rather, walk before we fall flat on our faces and have another ninety uninterrupted and essentially undifferentiated years of centre-right economics and the worst forms of cheesy ethno-nationalism? No? Oh well...
((*) I'm for convenience here including Sinn Fein in the "left" concept, albeit "semi-reformed extrapolitical irredentist ultra-nationalist xenophobes with some populist 'oppose everything' policies sprinkled on top" would be my own personal characterisation.)
Also springing immediately to mind is the snitty reaction to Obama's re-election from the likes of Neil Gaiman and his infamous "now go do a bunch of stuff you didn't run on doing, or that we've failed to elect the Congress that would allow you to do" snarcratulatory tweet. (Yes, I've complained abput that one before, but it's such a "fine" example of the genre that I struggle to see past it. "Entitlement issues", indeed...)
If one is dissatisfied and disillusioned by not having one's full will of the rest of the populace without having bothered to convince at least 50%+1 of them to agree with one in the broadest terms, one really isn't fully on board with the whole "democracy" concept at a pretty fundamental level. (I suppose the right is at least as guilty of that as the left, but traditionally are "better" at expressing it, rather than disengagement and counterproductive fracturing, in more "productive" avenues like populist trolling of the electorate (pretty much all of them), fiddling the voting system (looking at you, GOP and UK Tories), and of course the perennial favourite, political violence (hi again, SF!).)
I'm not sure I entirely understand your point about assessing preferences in the light of a "significant chance of winning". I might be missing subtleties or oddities about the Australian system(s), but I understood that it uses AV/instant runoff/single-member STV for most purposes, with assorted bells and whistles like compulsory voting (grand) and compulsory total ordering of candidates (bizarre and pointless). (Are some of your elections multi-member STV, too?) I don't think there's any systematic basis for an insincere preference/tactical vote in such a system, Arrow’s impossibility theorem notwithstanding. Vote for your actual choice in order of desirability, but (in the "optional" (i.e. "normal") version of AV/IR/SMSTV), do at least hold your nose and continue your preference until you're genuinely equally unconcerned or despairing which of the remainder might get in (or confident they're unelectable anyway). Some people here (MMSTV) seem to think they've done their democratic duty after their "number one", or a number of preferences equal to the number of seats, or until they no longer have a "positive" preference, which seems to me to be odd. Getting to the polling place is generally the lion's share of the effort, rather than troubling to write down a few more small positive integers!
I can scarcely sufficiently express my venom for FPTP. The US version, as bankrupt and antidemocratic as it might be, almost makes sense compared to the UK, given its tradition of a barely-there party system of pre-electoral coalition. I think deep down even Gerry Adams and Neil Gaiman would probably realize that getting 36.1% of the votes cast is not a mandate for unchecked electoral dictatorship, but British Conservatives seem actually bewildered on this point, and quite unselfconscious when they propose "reform" to make themselves, being the "natural party of government", still more favoured by the systematic biases of the system. I hope they reap the electoral whirlwind of their shenanigans on AV and constituency gerrymandering, and leak enough votes to UKIP that both implode under the weight of their own Daily-Mail-addled preposterousness.