Long post ahead:
The FB picture and the replies really interest me.
I can't help feeling that we get bombarded so much by the work ethic and will-power= success, lack of work ethic and apathy = failure message that a growing number of people apply it to everything, and believe its the only explanation for all human endeavour.
The picture really sums up that viewpoint: obesity and poor health is purely a life choice brought about by stupidity and laziness; buffness indicates some sort of moral superiority.
Now, obviously, to some extent, most of us have a lot of control over what we look like, but as everyone else on the thread has pointed out, that's not the whole story. Plenty of people eat everything wrong and still look great - and vice versa.
Why is 'genetics' always held up as an excuse and not as an inescapable fact? Why are differences between two people increasingly attributed to their personality?
My theory is that it's to do with feelings of comfort and control.
The pizza-chugging fatty is drawn towards an explanation that emphasises lack of personal responsibility. "It's genetic," she says between mouthfuls. It's comforting for her to think that her appearance is beyond her control.
On the other hand, the jacked guy is all in favour of personal responsibilty - he wants to think he got that way simply by working harder than anyone else. The last thing he wants to hear is that he had a genetic hand-up. So he is of the opinion that with will-power, anyone can 'make it'. The inevitable corollary of this view is that those people out of shape can only be authors of their own downfall. It's comforting for jacked guy to think that his appearance, (and everyone else's), is the result of personal control.
I'm straying beyond the realms of diet here, but to broaden it out, both positions seem fundamentally flawed to me. Take Ah-nold: did he succeed solely because of his indomitable will-power? Of course he didn't! How far would he have got in acting and bodybuilding if he was 4'2"? Did he succeed just because he had the genetics to grow a massive chest and arms ( or that he could tolerate more AAS than everybody else - as someone who competing against him once told me)? No! - that drive and killer instinct pushed him to the head of the pack.
I guess we all tend to be attracted to belief systems that are pleasant and calming to us. The picture BTB put up seems to me another example of that.
Powerlifts: 500/363/573 @ 220 belt only
front squat: 403
dips: bodyweight + 176 x 4
military press: 232