Heard that before, but:
(a) no mention of the algorithm or even an expected bias
(b) accounting for algorithm failures (not enough people queueing, or high-load)
(c) 2 out of 7 queues (as predicted) with another BLM or SMN in a light party seems pretty close to reality in my experience (and I can't trust it is "significantly lower" without an adequate sample number and distance)
I wouldn't add an arbitrary weight there.
My "need" suggestion actually covers everyone: people who want more seals/desynths can roll on more loot with better odds, people who need items for glamours/gearing have more chances of getting them even if they're for another class, and if there is the need to adjust who gets what they can still communicate with the party as others suggested.
The chances of getting an item for gearing/glam, with 5 or 7 categories of items in the mix, are already worse than getting the highest roll out of 4 ppl.