I agree with pretty much everyone being mentioned here. I'd say a guy who fits this to some degree is Ivan Calderon. Fought on too long. Fought a killer of a power punching slugger in Segura and went to war for 8 rounds with him. Signed on for an immediate rematch with him. Then dropped back down in weight to 105 to take on a tuneup where he got bullied around, and then stayed at the weight to take on a lesser version of the exact same style with Moises Fuentes. I am the biggest Calderon fan out there, but I was stunned that people favored him, some by a wide margin, over Fuentes. Calderon could have gone down as one of the best undefeated fighters of all time had he retired before the Segura fight. 3 of his final 4 fights were against top tier pressure fighting punchers, the achilles heel to Calderon's style especially when he was as aged and faded as he was. A one fight example of this would be Daud Cino Yordan in his shutout defeat to Caballero.
How does he apply? Came out of retirement to face Johnson, I know. But he did that from the demand for glory and it's not as though he suffered some sort of legendary prolonged beating or ever fought again after that.
Riddick Bowe. His idiot corner should have stopped those Golota fights when he was taking that massive punishment. Now he's borderline ******ed.
Related to that you can also say Segura. Did you see his face in the Viloria fight- it was worse than Lebedev's (just do a google image search).
...but he won those. And aside from the 8 or 9 round beating from Johnson (which is not an all time beat down like Dempsey/Willard) it's not like those fights led to him taking any kind of notable damage. He was extremely tough. Never "too tough for (his) own good."
Chris Eubank is **** all compared to his predecessors, fighting UP was expected by TOP fighters in the past, and particularly the MW's & L-HWs taking on HWs REGULARLY... Eubank takes a back seat to literally dozens of great British fighters from WW - L-HW before him and at least a dozen MWs that blow him away!!!
Maybe the most obvious choice = Amir Khan. Khan would actually have more chance to win if he werent so tough, so his toughness is bad for his own good. Fighters like Margarito require their toughness to help them to win, so he is appropriately tough for his own good. Mosley isnt too tough for his own good, cause he actually would need to be even tougher to increase his chances of winning. He backs away and gets discouraged when losing, when instead he should get tough.