As hard as it may be to believe, people disagree on the facts. That doesn't make them stupid. Infact, in my own experience, people with radical political ideologies tend to be smarter than average.
What are you thinking of when you say that unrestricted capitalism leads to bad results. Are you thinking that, in the absence of anti-trust laws businesses will grow too large and become start acting like monopolists?
Or are you thinking that rich corporations will use their wealth to buy influence with the government, or the private protection agencies of anarcho capitalism?
If you're thinking of the first, this complaint is not particular to anarcho capitalism. Its more of a complaint against libertarianism/free markets in general. Anyways, I don't think this complaint is obvious. Anti trust is really hard to do effectively. The court cases take a long time and by the time they're finished the accused monopolist often has decreased in market share without the verdict.
Anyways, I don't want to go into too much detail on what you may or may not believe. Tell me more about what is so obvious about the failings of unrestricted capitalism and we can understand where the other side is coming from.