Poorly supported claims may be true, but without good reasons to accept those claims, a person’s support of them is irrational. In philosophy, we want to understand and evaluate the reasons for a claim. Just as a house that is built without a solid foundation will rapidly deteriorate and eventually fall, the philosopher who accepts claims without good reasons is likely to hold a system of beliefs that will crumble.
I think this is vital information as it can be applied to everyday lfie too. Without evidence, claims and reasonings are very poor and therefore lacks external validity. Evidence aids reliability and trusting of the intial source.