A while back I posted a report on an RA between Sebby and Dagget departing LAX on the ATC issues section. Unfortunately the thread has gone but the gist of it was that and RA occurred between a heavy 744 and a BE200 at 17000 feet.
It is similar in that it could all have been avoided by a simple change of clearance to give 1000 feet vertical separation rather than 500. In the SFO case a delay to the 777 take off by 15 secs would probably have solved the problem, or is it that the controllers are so focussed on flow rates (due to management pressure) that they don't want to do that.
A TCAS RA is a very rare event in commercial operations, I have only seen one in 20 years flying 744, 757, 767 and 777 worldwide. It is not a normal manoeuvre and certainly on departure out of SFO with all the terrain issues, non standard acceleration heights etc would be very unwelcome.
No one wants to restrict GA, just an appreciation from US ATC that 500 foot separation will result in a TCAS RA.
I would far rather wait 15 secs or stay 500 feet lower than have an RA with the subsequent stress and paperwork.