Sanders hasn't gotten anything done in more than 12 years as US Senator, one of the most powerful elected political offices in the world. We don't need another gridlock president who can't work with others. Also, Sanders is a poor leader on social issues such as the issues that the Black Lives Matter activists are addressing. Same with womens rights. For example, he endorsed a woman who was running for office on the platform of opposing Roe v Wade.
When he finally DOES write something down, it's an embarrassment. The Medicare for All bill that he wrote and submitted to the Senate for ratification is a half-finished, poorly written job of an amateur. It lacks details so that the Congressional Office of Management and the Budget (OMB) can't provide a firm cost estimate. Some outside groups estimate the cost to be upwards of 30-40 Trillion dollars over ten years. Furthermore, Bernie left out how that would be paid for. At the high end estimates, the extra cost in taxes per person is about 10,000 per year. So this is your idea of greatness? A hapless, lazy, do-nothing Senator is running on an undefined measure that would disrupt healthcare for 300 million Americans and a quarter of the economy. Sanders cult is slavering over people who oppose what is essentially a half baked idea that was hastily scribbled down on the back of a napkin without much thought.