Comitatus or a promise is a promise

It seems comitatus was on every ones minds this week. Clynton points out "Comitatus is not about what’s proper or not, it is an agreement." I really didn't think of it that way. I just kind of saw it as Beowulf trying to prove he still had it, and was tough enough to take the dragon on. Ultimately we see he was wrong and he left his men and his people in a bind. 


I think you could even go so far as to say it was selfish of Beowulf to risk his life like he did. He wasn't showing much concern for his people when he chose to go fight the dragon. Wiglaf knew that Beowulf's passing would leave them open to attack from the Swedes so I have to assume Beowulf would be at least as aware of that fact as Wiglaf was. 


So my question is, why is it that the men are disdained and looked down upon but Beowulf's reputation is not even effected at all?