“Getting their own party members” to vote for something is not as easy as you think. Just ask the current majority leader how easy it is to push around his “Freedom Caucus”.
And the public option was not killed in the House. It was killed by Joe Lieberman, who was not even a Democrat any more. But he was the 60th Senate vote, he was opposed to it, and nobody - not even you - could have changed his mind. Consider that his final “F*** you” to his former party. So you can blame the people of Connecticut for that, not Pelosi.