Thats called not being able to put the fork down.
Nah...look at flex when he competed at 216-218 (93 Arnold, 93 Olympia) vs him at 230s. Even when he was 224 at the 97 Arnold he was a tad bit soft in those areas. Also look at Jojo when he was lighter, compared to when he competed a tad heavier. Melvin was a combo of laziness AND similar genetics (so, what you said does somewhat apply).
Guys like Ronnie, Chris Cormier, JD Dawodu, (and maybe even Bertil Fox), Shawn Ray and Dex don't really have or had that those issues due to having different genetics. All the names listed---Brian Buchanan, Flex, Jojo, Melvin, Adornis Cherry, Darien Bond, Beyeke, Rhoden (maybe add John Sherman to that list) all have that same look---extremely small waist, full round muscle bellies, and some have that "thick skin look"---you know like Vic Richards. Which means that dieting is probably harder for them that someone without those genetics. Add in possible kidney issues due to diuretic use, some may be less inclined to come "peeled", and rely more on their shape.
Maybe it's kinda like Jay and his wrinkly back?