Just more "yap-yap" garbage that has crept in and eventually stays forever. To extrapolate the idea to area control:
xxx Climb FL260........Climb FL260 xxx......xxx readback correct.
xxx turn right ten degrees.......turn right ten degrees xxx....xxx readback correct.
Is one clearance more important than another? If someone makes a case for this, then that case would have to include all executive clearances. At a stroke it would paralyse the whole UK airspace system. Did you know that the traffic capacity of some London sectors is limited by R/T loading alone?
Best practice would be to listen to the readback and only respond if there is an error or omission.......unless you're paid by the word, or work at a quiet unit and need the exercise, or like the sound of your own voice.
To be serious for a moment......I appreciate that it might roll off the tongue more fluently and naturally when combined with another message portion such as "xxx [readback] correct, report ready etc etc"....or similar.