I'm confused.  Can someone more familiar with market trading explain current observed behaviour to me?

When Bitcoinica was in full swing, I understood the ask walls.  You go 1000 BTC short at 10:1; then you put a 10000 BTC ask wall up on Mt.Gox.  You rely on that wall to drive the price down, then collect your Bitcoinica short profit.

There is now no Bitcoinica.  What does the owner of the 10000 BTC ask wall want to achieve?  If you own a lot of bitcoins, don't you want the price to go up?

I'm not complaining about the walls, the people posting them are as free to trade as anyone else is; I'm simply confused as to what they are trying to achieve.  Perhaps I am simply not thinking evil enough... could someone who is more evil than I out there tell me what I'm missing?