Don't clear a act and give up because you didn't get any good loots. Farming on Diablo is like gambling. Chances are you will only keep 1 out of every 20-30 drops or so. But keep in mind YOUR AIMING FOR THE JACK POT.
If your gear isn't good enough to farm efficiently I would recommend farming gold or try a different act. Act 1 with high MF seems to be the best for most players.
I currently farm act 3. I clear the whole act 4-5 times a week and usually get at least 2-3 items worth 1 mill + (I'm able to kill 80% of all elites/champs). Takes me 2-3 hours to clear entire act.
When I first started farming act 3 the only MF I had was from NV. 0% from gear. And still was able to get at least 1 item worth 1 mill + a week. Now I'm using 150% MF and my chances of getting a good drop has increased (not a whole lot but a little bit of a difference)
But like i said- YOUR AIMING FOR END GAME GEAR. I don't keep items unless their worth 500k +. So far the best item I found a was a weapon with 950 DPS and 380 LOH. It took 2 weeks to sell and I got 15 Million for it. Also found a amulet worth 8 mill.
This is end game people. Your not going to get a good item every time you clear a act and that's the way it should be.
NO- I DO NOT THINK LOOT SHoULD BE INCReASeD. It's fine where it is. This is end game people.... It should take some time. AH is already flooded as it is