[ashark]

I think it's both the 80s/90s low-fat push, yes, but also an aversion to eating anything that reminds us it came from an animal. Chicken breast, preferably breaded to make it look even less like something that was ever alive ("nuggets", even better!), pre-sliced turkey breast, cured meats, fish reduced to scale-free filet or stick form, all acceptable. Boneless steak cuts if we want to feel exotic and wild (cooked to medium if we really want that cave-man experience, of course—medium-well otherwise).

Bones, skin, limb-shaped things in general, organs certainly, blood, any recognizable bits really (heads on fish, oh man, that's right out) are to be rejected with expressions of disgust.

Outside the serious hunting/fishing set and self-identified (in their own minds at least) cultured and/or foodie folks, this is the norm as far as I can tell.

[johnbrodie]

Convenience alone could also account for all of the examples you mention. You can see the same trend in non-animal products as well - my wife just brought home a pack of pudding twice as expensive because it's in an "easy to eat" pouch that doesn't require a spoon, unlike a normal pudding cup.