Here's the way I see it:
-Murphy holds a bronze, has won a world title, and is probably in the top 5 or 6 all-time in his distance for US runners (D. Solomon, Symmonds, Grey, Brazier?, I'm guessing he's 5th). This year, he won the US title, ran 1:43.17 which was a world lead at one point, and made the final. Just being a repeat Olympian, I'd call that a pretty solid year.
-Galen Rupp is a 4-time Olympian and two time medalist and holds many records. He's not a guy with great marathon times so I'd call 8th not particularly bad
-Centro is a 3-time Olympian. Considering Craig Engels and Henry Wynne were faster than him this year in addition to Nugusse and Hocker, I'd call simply making the Olympics for a 3rd time a pretty solid year for someone of his advanced age.
I don't know if they're out talking about how disappointed they are but Jenny Simpson manages to put on a positive spin to whatever season she's had. At Doha she didn't medal but she said in the mixed zone she was happy with aseasonal best.
I'm more impressed with athletes who can lose with grace. I'm not saying Murphy, Rupp, or Centro cry like babies when they lose but openly projecting the qualities of "I'm ok w/my season" is a lesson athletes can also spread to the people that look up to them, most of whom are gonna have failed seasons.