Why are USA Heavyweights so poor?

[Violent Demise]

What’s going on with American Heavyweights?
For almost 100 years America has dominated Boxings heaviest division but now no one.

Lamon Brewster's non effort last night against the china chinned Wladimir Klitschko just about summed up the pathetic state of the USA Heavyweights.

Americas other best Heavyweight Shannon Briggs surrendered his WBO title meekly and now Brewster does the same. Currently no American Heavyweight holds a version of the title (with the main 4 bodies)

Why are American Heavyweights so poor? Are there any prospects on the way?

Do you have something against fighters from other countries?I could care less where they come from, if they can fight and are entertaining who cares?

Why would I be against fighters from outside America? I live in Europe!
No I certainly don't mind where good Heavyweights come from. Its just there are none at the moment.
Chagaev is probably the best of the champions. But the contenders are poor and like a few have said its not just US Heavyweights.

My question is about American Heavyweight's as the US has given the World the top Heavyweights around for 100 years. Not just the Superstars but people like Ron Lyle. Ron Lyle would have broken Wladimir Klitschko or Ibragimov in half.

So is anyone on the horizon? Anyone know about the Kronk fighter Isaih Thomas?
Is Chris Arreola any good or another Vinny Maddalone? Tony Thompson?

Isiah Thomas is suppose to be the next great heavyweight.