Once upon a time there was a libertarian who wanted to end taxes within his lifetime. It was his mission in life. He goes around telling people taxes are bad and involuntary, and the taxman is taking money backed up by guns, and that's wrong. Suppose he succeeded as far as getting the political debate in America to be significantly about taxes. Would that be good? Who knows. Maybe not. Should he assume it's good on principle? No. In fact my guess is that taxes would not be efficient to reform anywhere near that much, today; once taxes were reduced a bit there'd be plenty of lower hanging fruit, and reducing taxes the last, say, ten percent would be extremely hard and shouldn't be a high priority.
I am doubtful that he's much of a thinker. It's easy to take a naive/simple liberal policy, notice we don't fully implement it in our society, and say we should. What's harder is looking at what concrete steps would improve things, and how to make them happen. He has no idea how much knowledge it would take to do without taxes, and he isn't trying to contribute to creating it; a real reformer ought to work on creating the knowledge needed for reforms to happen.
Should he go ahead anyway? I don't think it can do any harm, and I think he'll have fun and perhaps meet interesting people and learn something. And if he fails, he may learn about a few of the practical difficulties, and perhaps he will react to that by thinking about how to overcome them and end up creating some useful knowledge. He will only get attention if he is persuasive to others. If he's wrong and it's bad, well so are they, so his part in the harm is miniscule. And anyway we have a system for deciding what issues to focus on, and as long as he follows the system who can fault him? The system is to persuade people, and it's the best system we know. To say he shouldn't pursue his ideas within that system is to say you know what's good and bad better than the system -- it's saying you know more than our political institutions, and ought to override them -- which is deeply arrogant and foolhardy.