In simple terms, 'vote blue no matter who' has never been tried because every time there is an election, articles like this appear dampening the progressive vote. The majority of the US is opposed to the current wacky reactionary conservative populism but that rarely manifests at the ballot box.

Practically speaking everyone who opposed the GOP should vote blue. If you lost your primary then this cycle you have lost the argument and you should stop whining and vote for the guy or girl that the primary voters settled on.