It's also plain wrong. Candidates win on minority shares in FPTP regularly, especially when there is more than two candidates.
In the UK for example, it's pretty common to win your seat with just 40% or less of the vote. The desires of 60% or more of the electorate in that constituency is simply ignored - a majority can vote for someone else entirely, hardly a reflection of the electorate's desire.
> I think you're overstating it when you say that it leads to situations where anyone who didn't vote for the winning candidate might as well have not voted.
I'm really not. The outcome remains the EXACT SAME if everyone who voted for a losing candidate stays at home. This isn't really my opinion - it's a widely known limitation of FPTP electoral systems.
For you to think that your vote doesn't count would mean you know in advance that your candidate will lose. You don't.
How is this tautology helpful at all? Why would we want this definition of what the most desirable candidate is?