Actually, just picking up a 3-pack Clone I have nearby, it's 7 separate pices (I think they all vary though), which means 3 - 4 separate sculpts requires about (since the pieces do vary) 21 - 28 molds... more or less, there's definitely multiple molds for the same sculpt, etc., but that's simplified for the sake of conversation...
With mold toolings being the highest fixed cost in a figure's development, I think these variances in numbers are important. That's thousands of dollars difference between doing 3 - 4 pre-posed sculpts compared to one sculpt with many points of articulation... That's not to say that there's not profit being made on both though of course, just really semantics that the reality is that the 3 - 4 pre-posed figures did cost more to produce than a single SA styled body.
Whether Hasbro intended these variants and all with the thought of profit in mind, I think profit's always their motivator but I don't think people would've NOT bought a SA 3-pack over a pre-posed 3-pack, and potentially they could've made a scant bit more per unit had they gone the SA 3-pack route in the first place. Not sure what their motivation is to go either way though because I don't see them making LESS if they'd gone the other way than they did.
I think articulation, since it is an added cost, is indeed something they've been slowly forced into. It's a competitive issue in the toy industry in general where one company's outdoing the other... It's rampant in the 1:6 market which has seen revolutional leaps made by one company's attempt to outdo another, right down to the patenting of some of the innovations being made by some of their creators. I think Star Wars has moved the level of articulation in an effort to be more competitive on the shelf to comparable toy lines... Whether that's the case or not though, who knows, but it's definitely been a gradual thing that Hasbro's been questioned on and seemingly reacted to. I guess I maybe don't give them enough credit for being "devious" enough to plot out an articulation scheme that, for all intents and purposes, doesn't benefit them all that much to play it out to its supposed end.