This is the second argument against the law of attraction. 2. The law of attraction insulates the believer from feedback
The most important principle of wisdom is this: Learn from your mistakes! This phrase sounds simple and trite, but it has profound implications. The first implication is that there is an objective reality. Our understand of reality increases as we receive feedback from our actions. Feedback is what allows us to learn from our mistakes. The second and more subtle implication is that we must never hold any belief that if we were wrong, we would believe it anyway. This includes beliefs that are framed in such a way that they would still seem correct no matter what the outcome.
The law of attraction is such a belief. Those who believe in the law of attraction attribute their success to their attractive thoughts and beliefs. When they are not successful, they think that they just didn't believe hard enough. This is a very narcissistic view of the universe. It points to the self as the cause of all things in the universe. If the law of attraction is true, then the Jews must ultimately be blamed for their own holocaust because they just didn't believe enough to attract success into their lives. This is one reason why I find the law of attraction to be so offensive.
The law of attraction A commits the fallacy of confusing correlation with causation(post hoc ergo prompter hoc). If the believer is successful they believe that their thoughts are the proximate cause of their success. Now it is possible that the belief in the law of attraction could have given the believer ignorant confidence. That confidence could have been a positive influence on their success. So in an indirect way, a belief in the law of attraction could lead to positive outcomes. But this in no way justifies a belief in the law of attraction. If it did, then confidence-enhancing drugs would be justified as well.
One who believes in the law of attraction will always think they are right no matter what the consequences are in reality. You cannot really reason with such a person. All you can say is, "I don't have to convince you. Reality will do that for me."