Hermie,
So you're suggesting that we (ATC) do the steering, and the pilots... do what? Put the gear and flaps down, and remember to return the stewardess to the upright position?
I issue headings when I HAVE to, not because I want to. Issuing headings increases your workload - in your scenario I would have to make sure I turned every aircraft left or right at a particular point - some concentration required. What if I have 10 or even 20 such points in my bit of airspace? And lots of aeroplanes all wanting to go different directions? S***loads of concentration required.
The primary task of ATC is to keep them apart and there is more than enough work to do in achieving that. But steering as well? No thanks.
The Lizard
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Do the dance and become a lizard