Philosophy isn't so much about producing conclusions for others to adopt as doctrine, but the process of arriving at conclusions for others to model, which makes trains of thought that lead to contradictory conclusions especially interesting to study.

As long as there has been philosophy, there has been sophistry. The adversarial use of bad (but very convincing) arguments was a problem in ancient Athens, and it's a problem today. If you can't even find the fault in an argument made in good faith, you're absolutely helpless when the faults are made in bad faith.