AC
I have to agree with you and also del Prado here. After working in a number of ATC systems around the world where in TWR,APP and Area environments,I believe it does come down to lack of awareness from the tma/sector staff.
From an app sense a high performance turbo prop will easily keep pace with a jet from around 30 miles out and on many occassion I have had a Dash 8 give me 245kts (even 250kts in some cases, and they can keep this going to very close to the field as you say) and only a minor speed reduction to maybe 280 kts may be reqd on the jet (they have to reduce to 250 any way out of 10,000ft). If its the area guy at around 100nm out then it maybe a different kettle of fish especially depending on flow control as well.
If they try it a few times and then realise it can work and actually be less of a workload for the controller and keep a more consistent flow to the traffic picture than having a few acft on vectors and with speed control.
cheers