Don't you have those predictive vector thingies that show you clearly who is doing what? I saw these on a video of a Scottish radar screen presentation after I complained about being punted out of the way to allow a 737 70 miles behind to get to the runway first (but that is another story!)
Many pilots do not necessarily fly at a "standard" speed on descent, nor are they required to; believe it or not most airlines still allow captains some discretion when it comes to slowing down a bit. Possible reasons could include:
Technical problems
Pressurisation difficulties
Turbulence
Cabin crew struggling to get cleared up
Holding ahead (or rumours thereof)
The perils of arriving early (ie no gate, or ramp staff)
As none of the above are emergencies (or even urgent), the current trend to eliminate unnecessary RT may well be why you don't hear more (frustrating as that is for you, I guess).
I kind of thought that they taught controllers to exercise judgement, and I would have thought that part of that included not assuming anything such as descent speeds, but WTFDIK...
If not, maybe we shouild just use TCAS and save a fortune on your salaries...
