The warriors who have respected you all these years — Bhishma, Drona, Karna, Duryodhana and others — will conclude one thing: Arjuna was afraid. That is what the world sees when someone walks away from their moment. Not the inner turmoil, not the moral anguish. Just the retreat.
Krishna is not manipulating Arjuna's pride. He is stating a social truth. When you quit a responsibility that everyone knows is yours, people do not pause to analyze your motives. They see a person who could not face the moment. And the higher the pedestal you stood on, the further the fall.
The word 'laghavam' — insignificance, smallness — carries real weight. Arjuna was 'bahumata' — greatly honored — among these warriors. To go from honored to insignificant in one decision: that is the cost Krishna is laying out.