Erm... it's not an excuse now, though is it. Such 'news' could promote an 'excuse' culture for being more overweight than necessary, as with all things, there's a limit.
The 'rounded-bottom' theory is in conjecture with the dangers of having an 'apple-shape', which truly isn't healthy because it signifies a fat build-up around your vital organs.
While it is much more healthy to be a normal, healthy weight, with curves (about a size 12-14); anything above starts to become a serious burden on the body - regardless of where the fat storage happens...! Plus - it seems it's a fairly genetic thing. Some people naturally store fat in their bums, some in their tums...!