This is a tough question. I personally don't like the hardline positions that parties take as I feel it hurts open-mindedness in policy making. On merely principled grounds I think parties are a terrible way to run a country. The problem arises when we attempt to run the country without them. How would we choose who to vote for on ballots? How would individuals achieve any sort of recognition? Congress and the functions within it are entirely dependent on the existence of parties. They organize and vote together while some congressional functions are entirely dictated by them, such as choosing the Speaker of the House and the Senate Majority Leader. Parties are also an incredibly strong factor in mobilizing voters.
To more specifically answer the question, we need organizational groups to help run the vast bureaucracy of the US, but not ones that demand cooperation in ideals and voting.