That's some pretty idealistic thinking, next level. Conceptually I agree with you 100%, but to expect that from our current system is not practical, nor realistic, imo. So it may make the individual feel good, and better about themself by voting for someone who claims to share those concepts, but has no realistic chance of winning. So in a practical sense, voting for that third party candidate is truly throwing your vote away.
On the other hand, depending on where you live, it may not matter anyway. If I lived in a deep red state and voted for the Dem candidate, it's just the same as throwing my vote away on a third party candidate. Ultimately, all that does is give you cred when we're all standing around the water cooler at work, bitching about those dayum politicians. Well, at least we used to be able to all stand together around the water cooler, but not anymore.