Interesting fiction, but Apple goes for simplicity.
A more likely compromise, I think:
1. Let any app (via efficient background updating, not "running all the time") update its own icon. Icons become display widgets when needed; tap to launch and see/do more. Like the way OS X icons can display live info. Like Calendar (but probably not constant animation like Clock).
2. Let any app choose "widget" as its screen size: when launched, it opens exactly like a folder, into a 3x3-sized rounded box surrounded by wallpaper; tap the background to close it (or click home) exactly like a folder. In addition to the size and quick-exiting, such apps would have to conform to whatever standards Apple implements (size/memory limits?) to allow true instant launching without load delay. Result: a bigger widget than just an icon, with room for interactive controls, but easy to toggle on/off.
The two would work well together, but could be used separately by developers.
This would be widgets without complicating one of the great things about iOS: the simple home screen that always works the same. That's a big benefit to most people. I wouldn't want them to abandon it lightly--but widgets do seem likely in some form, one of these years.
Second best: allow people to replace a row (not a box) of 4 icons with a widget bar. Probably the top row, and probably visible on all pages: clearly separate from, and not interfering with, the home icon system. You could swipe it sideways to cycle through more than one widget; or half-bar widgets might be allowed.