Because it is not logic, it is a childish tantrum.
If their guy doesn't get picked, they quit, take their ball and go home.
It’s always been that way on here, if their guy doesn’t get in they sit and whine and do what ever they can to undermine the final candidate so they can say “Look, see, if you voted for my guy we would of won”, it’s easy to make a statement that cannot be proven or disproven, but it makes them feel better.
We have too many that would prefer to create a self predicting prophecy than to actually do something to push our cause forward.
Their ego means more to them than actually doing something.