Honestly I think its just a matter of luck. I havent done ifrit more than 10 times and have gotten 3 weapons and 1 totem. 2 of the weapons were the ones I was actually looking for, harpoon and knuckles. My friend, who was doing runs with me, got 3 weapons over the course of 4 consecutive runs. Maybe it was 5 runs, can't quite remember how many we did that night.

Some ppl obviously have terrible luck, but that is hardly Square's fault. The drop rate is definitely not that bad; if they made it any better ppl could be 7/7 on ifrit in the matter of a day. Just keep running it and you'll get what you want eventually. It took me two or three nights of Ifrit to get what I wanted. Your mileage may vary.

The only thing i'd change with primal drops is to make weapons you don't want good for something.