'stealing votes' lol like all votes by default BELONG to one candidate or another, or the assumption is it HAS to be a REPUBLICAN or a DEMOCRAT? You've been stuck in the two party duopoly far to long. R & D both put up shit candidates this year. Johnson is earning the votes, not stealing them.
In a first-past-the-post system like ours, it's almost guaranteed that it will devolve into two parties. Better to vote for one of the majors that will partially represent your interests than risk the one that definitely doesn't represent your interests because of a split vote between a third party and a major party.
The major faults here are the assumption that all republicans and all democrats are monolithic in their ideology and to seemingly only give a crap about it every 4 years. Where are these third parties at state and local levels? How many seats in statehouses do they hold? How many governors? Senators? Congressional representatives? Every 4 years, they trot out as a third party contender, but they're trying to build a house starting at the roof instead of starting with a foundation. Want better candidates? Vote at the more local levels, vote in primaries, etc...