which is highly practical and therefore very realistic. Many of the fights are in close quarters. A camera/POV in those quarters will also be cramped and not see all the action, just as the combatants don't see the entirety of the action. This is part of the reality of hand to hand combat.

This page talks a little about it:

http://www.tandao.com/2012/02/09/jason-bournes-fantastic-fradulent-fighting/