The real question should have been Klitschko are to blame for the decline of the heavyweight division? (Do not know why they are ruining) the answer is NO, is the sanctioning body of professional boxing and greedy developers in search of easy money are the main culprits. Currently, the WBA, WBC, IBF and WBO organizations are recognized, but then there is the FMB NABF, IBO and WBU with all these sanctioning bodies, promoters and boxers of lesser rank to which we all seek money from him, so it is not surprising that the league has been reduced.
The Klitschko’s are not ruining Heavyweight boxing (and I admit that it was short sighted to say) but I reckon they do fail to appeal and connect to people outside of Eastern Europe. The heavyweight division needs a charismatic icon, somebody that excites a crowd just by the utterance of his very name. This was once Muhammad Ali a man who had the whole world in his corner. People remember him for his fast wit and humor, but mostly for great fight’s like RUMBLE IN THE JUNGLE and the THRILLER IN MANILLA; these fights had the whole world watching and have long been talked about as some of the greatest bouts ever. Boxing needs this drama and I don’t think that the Klitschko’s last couple of fights has really been delivering on that.
I do not think the problem is that Klitschko years are not as charismatic or not a spiritual personality of Ali, who is there fighting styles and personalities more relaxed, not paid U.S. television. I think it's the same for most other talents that came from the former Soviet Union, people like Adamek, Povetkin, Denis and Ruslan Chagaev Boystov are other names that are leading the division in Today, these people are not really the kind of iconic showman, who are more focused on winning, adequate training, as right and doing the job of being an artist. This is probably one reason why people are not interested in trucks and turned their attention to the welterweight side of it, since it offers more excitement.
So if there is a spark? America has long been the boxing home entertainment, Las Vegas and New York has always been to put the show especially the heavyweights. America has a decent form of heavyweight Tony Thompson, Eddie Chambers and Chris Arreola, but all three of them are lost to Vitali and Wladimir Klitschko at some point in their career, and why these losses, none of them have really done all that distinguishes them.