Can't quite agree with you on this one, bc. There is nothing magical about 16" centers. They are right for some applications and wrong for others. The diamond markings on the tape measure are just another aid to the carpenter/framer and I recall them being on tapes a long time ago, back in the 50's anyway. But then I remember plywood from back then as being so hard you could hardly drive a nail through it.
The way that they have cheapened construction is another issue but I'm sure glad that we have copper and PVC pipe now, for instance. If you had to cut and thread galvanized pipe or mess with cast iron, you would see that not everything new is bad.