I can't speak for anyone else, but I recently made a genetic lottery comment and if you read my posts in this thread, I am certainly not a celebrant of emaciated models, but I am not a radical anti-thinspo either who assumes that every visible clavicle or hipbone means an ED. To me, winning the genetic lottery means being tall and thin (but not frail or refugee-like) with the right hip-to-waist-to-bust proportions and a having a face and body that photographs well. It also means having the right look at the right time.
I'm with you! I only recall seeing the term once in here, however, i was referring to seeing it around the internet in general really, not the fashion spot. Some of the dialogues/discussion around many of the celebrity/fashion websites out there are simply riddled with it, and not in a healthy way.
My personal 'lottery' ideal would more likely be petite and slim, along with the photogenic face, etc. But yes, in the modeling world, your description makes perfect sense.
***hurghh! I was replying to an earlier quote here, and completely messed up the code, sorry folks!***