The problem here sunny is the mix of aircraft types and the "safety" controls each different company has placed on their operations, such as crews meeting certain gates and approach criteria.
An example of this is when Jetstar first got 320s the old boys would fly it like they stole it, as time progressed approach criteria tightened and speeds were mandated. It slowed things down.
Mix a B777 at close to MLW or even better a MD-11 with a Dash-300 or ATR and then you get people saying well I cant go that slow and others that fast.
The answer is outside our backyard. 160 to 4 works, for jets and props. The problem is that companies internal policy for stabilized approach criteria to be established at ref+ and in final flap config can be hard to achieve if people need to reduce from 160 at 4 with only 300 feet to continue descent and be established & stabilized at 3 and 1000ft.
It is doable, and enforced in a lot of places, but like I said too many companies have dumbed down their procedures to lowest common denominator and the rest of it is either finger pointing or apathy.