The real explanation is that there's something about Elizabeth Warren that Republicans can't stand.
Democrats see her as very charismatic, personable, and inspirational.
Republicans always complain about how she's the opposite of charismatic and how they just hate her very voice and how she says things in addition to what she says.
They'd say that about George Washington, Abraham Lincoln, and Jesus if they had a (D) after their names. They are totally and completely intellectually and morally bankrupt.