Better that you should stop lying about people and ranting on message boards regarding a political system you obviously know little to nothing about.
You're in a foreign country trying to lecture Americans regarding their own political parties when you've repeatedly shown complete ignorance regarding basic voting patterns in this country while likewise insulting said Americans and even outright making up things about them just to feel morally superior.
I've already told you -- if Sanders wins the nomination, he gets my vote and the same goes for Biden.
That's "unity" -- not sitting here asking why people should vote for Sanders (or Kamala, or Beto, or Buttigieg, or Biden) if they win the nomination.
The only reason this is even happening is because Sanders supporters can't accept him losing -- if he had more votes, he'd be the nominee.