One of the reasons for this is so that in the event of engine failure, a descent through cloud does not have to follow, ( with no AI) and gives time to glide through the hole through which the solitary blade of grass can be seen , so one foot above a broken layer would not be legal VFR.
Nah, you're reading things into the legislation that are not intended. VFR are designed around separation from other aircraft, and separation from terrain and obstacles. VFR apply to twins and instrument rated pilots too. You actually make the point quite well later in your post.