Interesting take. I agree any vote against Trump hurts him obviously. But since there is no way a 3rd party wins the state, and Hilary is the only viable candidate to defeat Trump, a vote 3rd party reduces her chances of taking the state and defeating him nationally. In addition, Utah still leans R, while 3rd party votes by R's hurts Trump, those vote would be more effective going to Hilary and adding assurance to Trumps defeat.
This speaks to my issue with 3rd party voting during the general election. This idealistic approach to candidates and the election is so short sighted and dangerous. See the 2000 election when Nader steered votes from Gore and basically ushering in the disastrous Presidency of George W. Bush. That vote set the country, and the world, back decades. If we have the chance to avoid a Trump presidency, you do it and don't look back. Those who refuse to believe this fact are naive, egotistical, stubborn, deluded, racist, or just stupid.