I disagree. The player who fights the mob before looting is not doing it "wrong" - people don't know how a queue works? Player A should take additional damage from the mob guarding the loot solely to prevent Player B from taking the loot while Player A battles that mob? The game mechanics encourage tackling the mob first, no? You can select and leap toward a member of the mob, but cannot select and leap directly to the loot.
What about the Data Raid mission in Section X, where there is one Elite and two Normals guarding the two tubes - which constitute the "loot", in this case - that each contain one Strong. I'm pretty well geared, but I can't handle one elite + two regulars beating on me while I take the time to scan two tubes that introduce two strongs to the mob. Net: I won't survive one elite + two regulars, + two (staggered) strongs damaging me for several seconds before I've launched a single attack.; I need to defeat the mob, heal up, scan a tube and take out the strong, move on the next tube. (Granted, this is an unusual case.)
Tying the "loot" (selectable object) to the area aggro logic seems a cheap, sensible, and elegant solution, to me; i.e., the player who most-recently has drawn aggro from the mob guarding the loot is the only one who can select the loot. (This might force the developers to update the game logic so that the mobs and loot respawn at the the same time/rate, which would be icing on the cake.) Why risk alienating paying customers when a mechanical change that could be tied to existing game logic is available?