Windsheer... Your bad language is NOT appreciated. If you cannot have a sensible discussion without resorting to gutter language perhaps you'd best go somewhere else.
However, your suggestion of aircraft being told to arrive over a certain point at a certain time would work at a small airfield with hardly any movements but Heathrow is extremely busy, operating at maximum runway capacity, and many aircraft arrive all at once. There are many variables.... perhaps an aircraft may be delayede on departure so it would arrive late.... or maybe there's a strong tailwind so it arrives early.
Heathrow does NOT invite everyone to arrive together. It's determined by the demand to airlines who try to do what their passengers want. I've already said that at certain times it can be quiet with no holding but how do you solve the problem of 50 aircraft per hour wanting to arrive??
BOAC.. you were dead lucky. Stories I've heard from BA pilots about Moscow suggested the opposite! I used to work in Africa in ther 60s and we used to hold aircraft then.. Most of the day we did zilch but come morning and evening rush hour it went bananas.