You realize that that is a flaw in the person, not the method right?
The Scientific method over many years has proved to be the best way to arrive at truth.
All scientific papers are subjected to the strict process of peer review. That tends to iron out most of the bad science. Yes, the conclusions can be made to fit an agenda but if the methodology in collecting the actual data is flawed it is sure to be uncovered in one year or 10.
Good example is the dead brain cells due to marijuana study.