You really expect 2 iconic wrestlers both in their primes to get squashed? Cena was beyond stale at this point, so this wasn't sacrifice he was making to help Lesnar. Now if he did something like this in 07 then you'd have a point.
No I don't, the way WWE booked since Hogan is the posterboy never loses clean, except for maybe a hard-fought loss to another top face every few years. WHich is why Cena doing this was so rare. Even when they finally had to lose clean out the door Austin and Rock didn't get squashed.
In 2014 Cena was still full time. He was around for all but maybe a month or two of the year after this. Cena losing a lot in 2017 made more sense because he's basically been done since, but he was still a full time main eventer in 2014-15.