Most Respectful Interpretation

In any confrontation, assuming that the person on the other side has good intentions, will almost always deliver a better outcome

Say you make a request to your bank to make a change to your account, which provides you with a higher interest rate. You do not hear back from them, what do you assume?

That they are working hard on your request,

OR

that they are just trying to avoid making the change and stonewalling you?

Most of us would assume the latter, while there are benefits to assuming the former.

Hanlon’s Razor - Never attribute to malice that which is adequately explained by stupidity.

People are often far more stupid than they are malicious. Incompetence plays a much greater role in delays than malice ever did. 

Further, when you assume the person at the other end is just incapable or going through a struggle you tend to approach things rather differently. Your first instinct is not to lose your temper but to either escalate to someone who would, hopefully, be more competent. Alternately, you might try to work together with the other person to find a resolution.

By comparison, when you force the other person into an adversarial stance, you often have to push the opposite side into submission. This can be far more time consuming and painful. Even if the other person is approaching the position with malice, if your approach is one of giving the other the benefit of the doubt; the two greatest creations of human society, guilt & shame, will bring them around to your position.

Summing it up, there is almost nothing to gain from assuming a worse motive. Therefore, always make the most respectful interpretation of the other person’s intention.