Also I don't appreciate the condascending tone about the amount of traffic in someones airspace. We all have our unique challenges and the airspace around Dubai has more than its fair share. Try working with the Iranians for a few days and see how you get on.
That's not what I was getting at, and I suspect you know it deep down.
I was trying to illustrate that the practice of having to restate a restriction seems not to be an unacheivable burden in parts of the world where traffic densities are high, and so where you might expect the procedure to be unworkable. So it can probably work in other areas too (which have their own local problems as you allude - but unconnected with this debate). The US invented aviation (in the form of mass transport we know today), so if they invented something that works and ain't broke, why fix it ??
I still think folks are losing sight of the fact that a clearance has up to 4 elements which are not intrinsically linked (unless a link is stated as part of a specific condition) - namely vertical profile, horizontal profile, speed profile, and time constraints. If you change one element, you only change that element in the reclearance, the rest remains the same (unless you have linked it to another element and then it requires restating or amending).
Otherwise, if we take the logic of a reclearance being everything previous is null and void, we would have aircraft routeing direct to their terminal fix and climbing/descending as they wished simply because we told them there was no ATC speed restriction on departure !!!