Why do we listen to relationship experts?

The majority of relationship "experts" seem to me to be full of themselves. As if relationships are like changing a tire, do steps 1 through 5 and you successfully attach the spare. If the relationship fails it is because YOU and nothing else caused it. Like to other person had nothing to do with it's failure. I look at these experts like I look at a psychic. What are their qualifications? Is their a school you can get a degree from? I know of psychology but that does not deal with trying to find a person to spend your life with. Why do they always talk about being single like it is a disease? Are they to tell us that being single is something to be avoided? It is impossable to be happy by yourself? I feel that we need to stop taking them as seriously as you would take a cardiologist. I know that everyone need advice in a relationship from time to time but the advice these people give is more based on what THEY want from a relationship and not for another person.