I've been a Bernie guy my whole life and will always like him, but frankly I'm a little tired of the way he divides the party. The Republican Party is for all intents and purposes 100% united (I don't consider the three candidates running against him in a Primary that won't happen to be a serious sign of party fracturing). The Democratic Party needs to be just as united.
The Democratic party has a serious problem, and calling for unity does not solve it. It's half 'Republican light', slightly less than Republicans plutocrats, corporatists, who go by 'moderate' and 'centrist' and 'blue dog'; and half progressives, who understand the country has taken a wrong turn since Reagan to plutocracy, and needs far more than another Clinton/Obama/Republican-lite presidency.
That we have a historic opportunity to overcome the overwhelmingly powerful interests for a once in a generation chance to elect the leader we need who is not Republican or Republican-lite, and how important it is we get a leader who will fight plutocracy, as uphill a battle as it is.
I *love* Bernie for his divisiveness, not because I want a divided party, but because the problem is the people who oppose Bernie, not the fact there is a division. There is and needs to be a war in the party which side will win, and Bernie is simply fighting for progressives to win that fight. Whichever side loses needs to then unite, just as Bernie strongly supported Hillary in 2016.
What you are calling for is simply for progressives to surrender to the corporatists in the name of unity - a disastrous suggestion that dooms our country to plutocracy. It's like saying Lincoln should have given the south what it wanted in the name of unity, instead of fighting for the country to defeat the confederacy and then unite as a nation.
I could even say it's like saying the Democrats should just surrender and give the Republicans what they want, in the name of American unity. Bernie is fighting for what we need, against the part of the party that doesn't want what we need, only a little. The progressives need to win control of the party, The time for unity is after the primaries.