In padme's case, it wasn't just that, but everything about Padme from eps 1 to 2 shows she's not one to die so easily and supposedly cares about things greater than just her and anakin. she even says "you're going down a path i can't follow" right? I can't remember exactly... haven't seen that movie in months. So her just going dead after fighting wars, surviving assasinations, and having two healthy kids just seemed ridiculous and completely against who she was supposed to be to me. In the end, I conclude that time was short and GL was in a rush to end everything in five minutes... A veteran of the clone wars dies not fighting for anything, just giving up. Kinda sad really but not the way it was intended.
edit: that's what I think too, mr. bungle. Padme is presented as a fighter so her dying due to Anakin's crazy insane force choke would have been so much more dramatic than suicide, the cowardly way out.
Oh now I remember exactly why this part always made me say WTF. Padme says "there's still good in him." right before she dies. So why does she die if there's still good in him? Bad writing as usual I guess.
Still, I look forward to those great pt edits that'll try to salvage Lucas' mess.