Gary Johnson is great on social issues but like libertarians he is for privatization of all government services, such as social security, education, healthcare, all the way down to road construction. It is in their platform. Personally I voted for Jill Stein because getting money out of politics is number 1 issue. If we don't nothing in this country will be solved. Currently lobbyist and big donors make policy in Washington DC. I know she will not win, but if she get 5% of the popular vote, they get ballot access, and federal funding as a legitimate party.
The green party does not accept super pac money so for them to get ballot access and federal funding gives them a head state in 2020 and allows them to build the party over the next 4 years. Jill Stein has already made plans for what they will do the day after the election. They plan on getting ranked choice voting on the ballots and opening up the debates.