So, appearantly I got added to a 'list'

[infinitezero]

If I put the same amount of time/effort into a run I should be able to roll on the same loot.

Sure. In a group where you weren't asked before hand (and by joining agreed) not to roll on it. If you join say a Brayflox group in Party Finder that specifically states "Battlemages Gloves reserved, do not roll on them" and they drop and you roll on them, you're a d***head. If you want them for yourself, make your own group or join another one.

If you roll on a reserved item, you're wasting the time of the person it is reserved for. They specifically want people that don't want or need that item, so if you don't fall into that category, stay out of their party.