In my opinion, Jesse James got exactly what he deserved.
A lot of people forget that he was a bank robbing, train robbing, murdering S.O.B.
Yes, Robert Ford was a coward. But no more than Jesse James who killed too many men way before their time. It's pretty bad for a movie in this day and time to try and make you feel bad for someone like this who should have been killed long before he was.
If I had lived back then, I would have spit on his grave.