What is the difference between Marco and Alfieri in the ending scene of A View from the Bridge?

Alfieri's quite stoical about everything that's just happened. A man lies dead and though Alfieri deeply regrets what's happened to Eddie, he doesn't hesitate to blame him for contributing to his own downfall. This seems a perfectly valid assessment of Eddie, given that he's very much the archetypal tragic hero. Nevertheless, Alfieri does still admire Eddie for the same reason as he admires Marco: unlike most people in life, he didn't settle for less.
Like Eddie, both Marco and Alfieri see the flaws in the legal system, albeit from radically different perspectives. They see that the system is concerned with law, not justice, and that the two aren't the same things at all. In stabbing Eddie to death, Marco believed he was getting justice rather than the half-measures provided by the criminal justice system. And although Alfieri, as a lawyer, cannot agree with that, he can still understand Marco's motivations, as he also can with Eddie's.