I'm not going to bother to respond to the original author, but you are making substantively the point I would have made. Electing Sanders would not have guaranteed anything he advocated actually made it into law. Look how hard it was for Obamacare to pass, with how many compromises made, and that was *WITH* a Democrat-controlled Congress. It's mind-boggling people think a lifelong gadfly had any chance of changing up to a third of the American economy in the face of the guaranteed scorched-earth opposition from both Republicans and all the related industries that would have been affected.
Back when it was looking like Sanders might be our nominee, I was resigned to the idea of "hey, four years of nothing getting done is better than our current Trumpian chaos and utter GOP heartlessness." Fortunately, one of the truisms of American politics once again proved itself: for all their sound and fury, the youth forgets where the polling stations are on election days.