Amaram stole the Shardblade, killed Kaladin's squad to hold the solution from finding out, and bought him into slavery as a deserter. Shardblades are priceless magical swords, and Kaladin legally gained that Shardblade, but Amaram resolved that a Shardblade would be squandered on a peasant with no instruction and ought to go to a noble like him who would conserve the entire world.