Yeah Chris Eubank always stated how he hated boxing, he thought it was barbaric and how the only reason he was fighting was for the money. "For all it brought him, Eubank has been no great advocate of the noble art. He admits to a distaste for boxing even before the infamous night when his measured punches put Michael Watson in a coma for 40 days and left him with permanent disabilities. That fight is etched into his consciousness. He has called boxing barbaric, and a mug's game."
Two I'd dispute are Gene Tunney and Mike Tyson. I think for Tunney boxing was a "guilty pleasure" - He learnt to defend himself, and sparred extensively with Willie Green before he ever harboured thoughts of doing it professionally. Before going into the Marines, he actually had a relatively well-paying job also. (Obviously nothing compared to the money he made boxing.) When he experienced his success fighting while with the Marines, he became somewhat obsessed with the notion of defeating Jack Dempsey, believing he was equipped to do so. I think if Tunney hated anything about the sport it was the nosey, judgemental reporters whom he publically humiliated after defeating Dempsey for the title. I'm sure he wasn't as passionate about pugilism as some others of the era (e.g., Dempsey), but he's on record saying the reason he declined invitations to big fights in the future, is because he thought it was a self-important gesture to be introduced at fights he wasn't involved in. As for Tyson, regardless of what he says I can't believe for a second he didn't love every second of fighting - Crushing fighters and being heaped with praise in a life that probably would've seen him dead or facing a life sentence had it not been for boxing. If you've read Atlas' book, you'll know what sort of power and respect he earned with his fighting abilites and how he thrived on it. I'm sure he "hated" it in his later career because he got his ass kicked pretty badly, got screwed by Don King, ended up bankrupt etc. But he was simply euphoric after a fight in the mid 80's. He got off on it.