What bothers me about the people taking the bit of time and effort to go vote for 3rd parties is that there's really no point to it. Making sure your own vote doesn't matter is insane to me when voting isn't mandatory. They could've just done nothing and achieved the same outcome.
Even if a notable number of people voted 3rd party, they're still going to be treated the same as those who didn't vote at all, because in a practical sense, thats what they are.
Any time you vote for a candidate that loses, this is the case. And of your preferred candidate wins in a landslide, every extra vote they didn't need might as well have been blank.