There is a big difference between playing LB against a CONCACAF opponent vs a CONMEBOL opponent that purposely looks to attack the left flank. Borstein did ok in 2010 WC but he was hardly tested, does that make him a good LB?
Bornstein was still learning the position in 2010. He went on to become an excellent LB in LigaMx. He should have received caps during the '18 cycle.