I take it you mean nowadays,because the 2 gents in Bazookas avatar had great physiques AND maybe a tiny little bit of talent too. Amongst other examples.
Because (with the exception of the Klitschkos and David Haye) the fat asses are guys that rely too much on their talent to get them through and aren't willing to put in the hard work on the other end that shows in the conditioning. A lot of the non talented guys think that if they lift weights and get a great physique that they somehow will become a better fighter. The conditioning will help them but the skills will be lacking.
1. They don't have to make weight 2. I'm guessing they feel so confident in there *skill* they really don't care what they look like...Use James Toney as a good example. 3. Lack of competition...A reason for training hard. These 3 reasons...Are why the Klitshko's dominant.
I agree, there isnt a limit so most guys dont give a ****. Check Danny Williams - he said "blah blah power... blah blah strength.." that gut was coming in at 19 stone because no one ever said "godamn, get your weight down"! I personally think that CW should be changed to HW and lift the limit to 230, and above 230 should be super HW.