make mob despawn take longer

Im not sure if this is the right place for this... so i apologize in advance.
Corpses disappear WAY too fast. When mass farming its hard to loot all and skin before they vanish. (seems to vanish faster than retail did) A tbc server i play on- they take alot longer to despawn. So I think its something that can be edited or toggled?
Anyway- despawn rate should be doubled at least.
My guildy level 80 was running me in deadmines and i only had time to loot half the corpses before the rest vanished. (and i was clicking like crazy)
If some 80 pulled the whole dungeon for Shadowfang keep or wailing cavern- i wouldnt get many skins since the mobs would disappear before i could loot em all- let alone skin them.
Is this a deliberate attempt to discourage high levels from speed-farming instances?

if warmane made them deliberately despawn faster, i'd wager it was to reduce server load, rather than to discourage boosting.