Ok, I actually went to look at the probabilities and yes, as the weeks go on the chances of getting neither of the coffers are very low. 5% by week 10, 1% by week 14. So you were right on it being extreme cases. My bad, It did seem more likely without the actual numbers.
...All that said, if there's something I've learned in all my years of playing this game is that the RNG is very messed up and many times probabilities mean nothing in it
And either way like I said before, they HAVE made improvements on the loot system so I don't see why those improvements need to stop. It's a lot better now but it could still be better. Also remember this is a MMO and there's a lot of people playing, even that 1% (within the X% who raids on pf) is gonna be a lot of people royally pissed off.