Or they could just implement a need before greed system that won't allow you to select need for an item that your current class can't equip.
We had a need before greed system in DCUO, but it wasn't class restricted, which kind of defeated the point. Anyone could roll need or greed, but if one person did need and 12 other did greed, the one got it. This caused no one to ever roll greed for anything. The problem I have with this system is that some people have more jobs leveled than others. Say I level BRD, GLD, LNC and ARC, but Joe only leveled LNC and ARC. To run the raid we need a BRD and I'm the only one in the company who has it leveled. This means that until someone else in the company levels their BRD up, I'm stuck only gearing mine up while joe can gear up both of his jobs. What if I max it out before someone gets theirs to cap? That means I can't go on LNC and work on gearing that job, which is ludicrous.
It's not always as easy as "find another BRD and invite him to your ls" or "Find a way to win without a BRD" (queue Kachi's class balance argument ). In that situation, a player would be SOL and at the whim of other players, which is a bad design in my opinion.
Well, I can't ever imagine you'd need an ideal setup for random instance, but SE's made me scratch my head often in the past. Furthermore, if your LS or team is making you take a certain class to whatever it is that you're doing, they should offer you priority or at least a chance to roll. In the latter case, however, a master-looter system would be best.But that brings me to another point; if your guild is making you go to raids and not letting you loot on stuff that you can use, maybe you need to find a new guild.
Now, as far as a need/greed system with randoms is concerned, if it's a queue system, there should be nothing holding you back from queuing from the class that you want gear for. Even in WoW, most people are pretty cool about letting you loot for your OS, but the game blocks you from needing any gear that's useless to your class. I could only assume that SE is smart enough to develop a system that does the same.
Perhaps I am misunderstanding you here. If the loot system does not allow you to roll for a piece of gear that is not equip able by your current class, then how would I be able to lot on a LNC piece when I am on my BRD?
I agree that there are solutions to these problems, but they are rarely easy or desirable. Join a new guild would be fine if it didn't mean leaving any friends i may have made and put me back at the bottom of the points list, or whatever priority system is in place. Master looter also falls prey to the evil of politics, unfortunately.