as do i. if i would have to guess my issues have been in the single digits. 9.9 times out of 10 people want to progress for the loot and as such i never really have any issues. quite a lot of times my team sucks yes, but i dont count that as an issue. i can solo all 3 as long as somebody gets the lures for me. hydro is the only one that cant be done without some sort of lure healing. and sometimes i get a great pug group and we take down 3 sets in one night.
i agree that you should be able to do it with less. say 3 people put in shards, other guy is just afk or something.. eidolon spawns after x amount of minutes and if they come back they can help but loot doesnt spawn for that player since he did not sacrifice his shard at the altar.