I think it would be fair if I could only greed on something instead of being able to need if I'm already wearing better gear.
I also need when I can, though when I see another person could really need it more than me I'll pass.

If I actually don't NEED it anymore I wouldn't have a problem if I could only GREED.
It would be even more fair in 8 man parties.
For example there are two Scholars in let's say Garuda Hard or so. One already has an ilvl 115 weapon, the other one is doing it for their relic and only has the ilvl 55 GC weapon. Yes, the better geared SCH could need it for glamours or GC seals, but wouldn't it be unfair for him to need that item the other SCH could need so, so, so much more?
Yes, the better geared SCH probably needs it for seals, but seriously, there are so many other things you can need on in all the duties you run, if you see someone else really, really needs that piece of gear I think it'd be unfair for you to still need.

Also you already get so many GC seals from other gear and from FATES etc. that you shouldn't be dependant on a handful of gear another player could need. Actually you have to look out that you don't get too many seals or you won't be able to receive them anymore. xD