I've seen a lot of posts about this on the forums and there was an issue tonight in PF about this also: Needing on gear that is of lower ilevel than what you have equipped.
Many people have a problem with it. This seems to stem from the idea that gear is just for fighting in and if you have something "better" that it is greedy to Need/Lot on the lower level gear. If you do then you are "depriving" other players of gear they "deserve."
I put these words in quotes because I obviously don't agree. The reason is pretty simple really: SE has made gear useful for other things than just improving your combat ability.
- Vanity. This is a legit endgame for some. I've seen people run dungeons 30-50 times for a piece of gear... for LOOKS. Isn't this the reason people farm ponies? Simply because they are cool to have? They don't do anything different/better from any other mount.
- Seals. I also think this is legit. Seals are needed for many important things (ventures, gear, mats, relic, Lucis tools, etc.) I think it's biased to assume that gear for combat (for you) is more important than these other purposes (for someone else).
- Desynthesis. I have GSM at 103. I'm trying to cap it before expansion. Farming gear is one of the few sources of skill-ups at this level. Again, this is an important endgame factor. Not only can I get skill-ups but sometimes items worth hundreds of thousands of gil.
Bottom line is unless you joined a PF group and explicitly asked for a certain piece of loot and it was agreed you could have it, then you don't have any more right to it than anyone else, regardless of the reason.
From SE's perspective, it is good that gear is multi-purpose because this creates more demand for gear and therefore more scarcity of that gear (and ultimately more running of content for that gear). Being able to Need on gear is a perk for those who play the job that gear is useful for. If you want a greater chance at a certain piece of gear, then you should play that job.
Please note, this is my own personal philosophy but the TLDR version is: you are owed nothing.