Why is libertarianism so infallible?

Libertarianism is the inclusion of every sapient being into the decision making process and all that logically follows from that. Utilitarianism is the objective of ensuring the most happiness for all sapient beings and all that logically follows from that. Sometimes they compliment each other, other times they contradict.

Discuss.

The main reason people accept statism is because they believe it is socialist. You are free to be socialist under a libertarian administration, you are just not allowed to use the state to force it on other people.