A green party majority is never going to happen.
One of the truths about representative democracies is that you need to put together a majority coalition to get anything. That means compromising on some of the things you want 99.9% of the time, except when you’re the lucky person right in the middle.
My circle of friends and acquiantances is significantly more progressive than the country as a whole, and I can only think of one who is even considering Stein. Even as Trump, a 70-year-old on his first job interview who inherited his fortune, has no clue about the actual job of being president, so too does a former town meeting seat holder have no clue. Had Jill shown she could run, say, a town or a division of doctors, she might be worth a second look.
As for the convention, as Hillary supporters, my family and I would have been furious if our (majority) votes had been discounted because the other side was louder and more insistent. I really don’t understand what facet of the convention you can righteously be angry about. Your candidate got less votes (it wasn’t even close), yet he got publically honored. Your values by and large got adopted.
We’re progressive Dems all of us, and we’d be the easiest people you’d have to convince. And we don’t just think Stein doesn’t have a chance, we PREFER Clinton.