There is definitely some truth to what you are saying.
I don't hold anything against Bernie Sanders himself.
Bernie Sanders himself is okay in my book.
For the record, Elizabeth Warren and Joe Biden are also okay in my book.
I don't think all Bernie supporters are what you describe, but there are clearly some who are exactly what you describe.
Two examples are Lash and Edgar.
That attitude that Bernie has to win the nomination or else, is very divisive