That argument breaks down because it’s more like the flavor likely to win is “sewage”, and that if it wins no other flavor will ever again be allowed to win.
Trump wasn’t going to win California in any scenario and if they can convince people to vote for the lesser of two evils even when their vote doesn’t matter they can successfully ensure that they never need to put forth a candidate anyone wants. Progressives will endlessly vote for conservative Democrats that will never do anything progressive and Christian extremists will vote for someone like Trump that is nothing they would want.
I understand the desire to convince people to disenfranchise themselves by telling them they must vote for someone they don’t want in election after election, so you never have to give them what they want, but not everyone is going to fall for it.