Open the door after defeating Dhuum/Urgoz etc

I've never understood why the door to the final room in Urgoz and UW (and maybe the Deep? Dunno, haven't done it in a while) remain closed after the boss is defeated. I know it doesn't make much difference to most people, but I know that some people (like me) like to go back and pick up drops that people missed, for example.

Is there a specific reason that those doors must remain closed after the boss is defeated?

If not, it'd be nice for them to open again once the boss is defeated. It'd be fantastic for the those of us who care about such things, and I can't see the change being hard at ALL since the mechanism of closing the door when the fight starts is already there, and it just needs to be reversed.

This is something I've been wanting to see for a while, and it'd be great if it was done.

Pointless. Not worth the effort, even if it is so little effort.

Correct me if I'm wrong...I don't believe there's any door/gate/anything in Urgoz's Warren that prevents you from going back through everything. I could swear that after killing Urgoz that I've run back and picked up drops that others left behind

There's already precedent . . . Mallyx (if you don't door glitch); door closes when you enter and reopens when he's defeated.

And Urgoz does have that door.
Trust me, I spent an hour trying to get past it. (I was bored, don't judge me. )

Also, for people who actually need the xp, it'd be nice to go back to get quests.