True...
I do remember playing with those little plastic Army men, fighting against my Tamiya 1:35 German troops and Tiger I. Fun times. I had many other limited articulation figures throughout my childhood too, and I can remember wishing they could move, even then!
There's also the mentality of model scene/dio grade stuffs. Those 1:35 guys do some amazing, but obviously static, dios. Personally, I'm not ok with having a more static 1:18 version of any of this. And I doubt most 1:18ers would be ok with it, seeing that we can pretty much get what we want - more articulated. Is it more difficult to design things for more articulation AND look good? Yes, it is. Is it worth it in the end, when you can achieve better poses, and change them whenever you want? Yes, it is.
This is the #1 downfall of all those BBi, 21st, Bravo, etc figures. Something as simple as a better hip joint allows for much more natural, and dynamic posing. Neck is a no-brainer.