Ok, so there are so many wild guesses out there, and a lot of them are related to the abuse of GH. I don't know how much I believe that organ growth is the cause. If organs were really growing that out of control, I wouldn't think that these bloated bellies wouldn't be uniformly round. I'd think that they would be uneven and lumpy. Our organs aren't all symmetrical.
I could see insulin being part of the problem though. We all know that before insulin was around, there were a lot more striations that we just aren't seeing today. What if insulin is creating more of a fatty marbling effect? This fat may be more resistent to fat loss, if the user continues to use insulin through his prep. Insulin may also account for the bloated bellies. I know that when I have blasted insulin at high doses, my stomach pops right out. I do not use slin when dieting and over my prep, it returns to normal. But someone like Jumbo was more likely running it right in, or at least closer to the show. Couple the smooth look and round belly with a loss in leg size, and you have a very unpleasent physique.
If you look at Daves suggestions today, he is very conservative with peptides. He suggest much less IGF than anyone I know. He suggests what most would consider low GH for national level guys, and not a lot more for pro's. And his insulin dosing is moderate at best. My thought? I've always wondered if he makes these lower dosed suggestions, based off of his own bad results, having used much higher doses. This is, of course, all speculation.