They might win 3 this week, but next week you might be the one to win 3.

The RNG works out over time - actually, you get way more loot in PF than in a static, especially as a tank/healer, because there isn't any sort of rule like forcefully assigning it to the DPS first or distributing it evenly. Although PF might result in you getting no loot the first week, one of the next weeks you'll get most of it. That's been the case for me in every tier that I've pugged really.