The legislature doesn't have to allow ballot access to every fly-by-night group that comes along. If they can't come up with the signatures, then it verifies they are insignificant.
That's why there are write-ins.
If there were enough libertarians in the state to elect libertarian legislators, this wouldn't be an issue.
Instead of whining about how the government (sense the irony here) isn't helping Libertarians stay on the ballot, why don't the libertarians run some grass (pun intended) roots campaigning to boost their numbers in the state.
But then again, when all you do is smoke pot, it is hard to get motivated to do much more than reach for the bag of doritos.