Why were people not mining on scrypt based multipools with their GPUs more if their GPUs are able to achieve such high amounts of hashrate? You could easily stack them to get well over 1 GH/s which would have earned you ridiculous amounts of money even early this year.
The timing was a bit off. BTC-ASIC entered the market and GPU farms changed to that to stay ontop. Multipools only started a little later, but by then many had already switched to ASIC and there's only so much power you can have at a location without major upgrades (=$$$).
